These are some conjectures about physics that are floating around in my head:
1. Sphalerons, the only Standard Model process in which baryon number and lepton number are not separately conserved, although baryon number minus lepton number is conserved, do not exist, because baryon number and lepton number conservation have the effect of making the energy density necessary for a sphaleron interaction physically impossible.
2. The baryon number of the universe minus the lepton number of the universe is zero, which in turn, implies that the number of neutrinos in the universe is extremely close to the number of anti-neutrinos in the universe.
3. Neutrinos are not Majorana particles and do not have Majorana mass.
4. There are no right handed neutrinos and there are no left handed anti-neutrinos.
5. Neutrinos do not acquire mass via a see-saw mechanism.
6. The Big Bang is at the center of the universe's time dimension. We are on one side of it in time. There is a mirror universe before the Big Bang in time, where due to entropy, time appears to flow in the opposite direction and the universe is anti-matter dominated rather than matter dominated.
7. Cosmological inflation does not exist.
8. Matter-energy conservation is absolute. Thus, the total mass-energy of the universe is constant and finite, although what this means in a global sense as opposed to a local sense is subtle and tricky due to the variations in the rate at which time passes and spatial contraction due to special and general relativity.
9. CPT (combined charge-parity-time) conservation is absolute.
10. The particle set of the Standard Model of Physics includes all fundamental particles except a massless spin-2 graviton that couples in proportion to mass-energy with a coupling constant that is a function of Newton's constant G. Quantum gravity does exist.
11. Dark matter effects are a non-perturbative effect of the self-interaction of gravitons, which are largely a function of the total mass-energy of the system and the extent to which the system is not spherically symmetric. Dark matter effects confine gravitons to within a gravitationally bound, non-spherically symmetric system to an extent greater than they would be if the system was spherically symmetric. The appearance that the amount of dark matter in the universe is constant is a function of early galaxy and structure formation. This implies that the tendency of satellite galaxies to be in the same plane of space is not a coincidence. This explains why the amount of apparent dark matter in a galaxy is related to the extent that it is non-spherical. This explains why there is relatively more apparent dark matter in galaxy clusters than in galaxies. Because gravity is so weak, these non-perturbative effects not considered in general relativity as conventionally applied, are negligible in systems smaller than galaxies.
12. Dark energy phenomena are due to systems with apparent dark matter not exerting a gravitational pull on mass-energy outside the system to the same extent that these systems would if they were spherically symmetric. The notion that dark energy is a substance created as space-time expands is an illusion. The Hubble constant and cosmological constant are merely approximations of this effect which are not fundamentally constant and are a product of dark matter phenomena over time.
13. Self-interaction of gravity effects lead to earlier galaxy formation than would occur in their absence.
14. MOND is a phenomenological approximation of self-interaction of gravity effects. Gravitational self-interactions give rise to the external field effect predicted by MOND. The strong equivalence principle of general relativity is not a true hypothesis.
15. There are no dark matter particles and there is no such thing as dark energy.
16. The sum of the square of the fundamental particle masses is equal to the square of the Higgs vacuum expectation value, which is a largely function of the weak force coupling constant. This sets the overall mass scale of the massive fundamental particles (i.e. the fundamental particles other than gluons, photons, and gravitons).
17. All neutrinos have a non-zero mass, even though the smallest neutrino mass eigenvalue is very small (on the order of 1 meV or less).
18. The three Standard Model neutrinos have a "normal" mass hierarchy.
19. The relative masses of the charged leptons, and the relative masses of the quarks, respectively, are dynamically balanced through W boson interactions, by a formula that is an extended Koide's rule formula. This inherently links the quark masses to the CKM matrix and the lepton masses to the PMNS matrix.
20. Koide's rule for charged leptons and charged lepton universality work because the neutrino masses are so tiny relative to the charged lepton masses, and so much more similar to each other than the charged lepton and quark masses, that the deviations from Koide's rule and charged lepton universality that they cause are negligible and undetectable with current technological means.
21. The masses of the neutrinos arise partially from their self-interactions via the weak force and partially from their W boson interactions with the charged leptons and the other neutrinos.
22. The point-particle paradox of the Standard Model is resolved because fundamental particles are fundamentally narrow waves, call them field excitations, and are not actually points.
23. There are no "extra dimensions" of space-time beyond the three dimensions of space and one dimension of time.
24. It is most accurate to describe the fact that quantum entanglement cannot be simultaneously respect causality, locality, and reality, as a causality violation. Thus, when one entangled particle's state is determined, that information goes backward in time to the point of entanglement and then forward in time to the other entangled particle.
25. The CKM matrix and the PMNS matrix completely describe the transition probabilities of the W boson, and the CP violating parameter in each of these matrixes is the sole source of CP violation in the universe. Forces with massless carrier bosons, i.e. electromagnetism carried by the massless photon, the strong force carried by massless gluons, and gravity carried by massless gravitons, can't violate CP because they travel at the speed of light and don't experience time, while Higgs bosons can't violate CP because it has no electromagnetic charge and has even parity, leaving only the weak force carries by the W and Z bosons as a potential source of CP violation. See also this Physics.SE post which observes that: "parity violating weak interactions forced the model to have massive vector and axial vector exchange bosons."
26. It is possible that CP violation actually has a separate fundamental source than the other CKM and PMNS matrix elements that just manifest inseparably from each other in what we can observe, and it is possible that the three non-CP violating parameters of each matrix can actually be described with fewer than three parameters in a deeper theory.
27. The probability of a two generation transition in either the CKM matrix or the PMNS matrix is equal to the product of the probabilities of each of the possible one generation transitions in those matrixes.
28. The beta functions of the Standard Model are slightly wrong, in a manner only discernible at very high energies, because they fail to include the slight impact of gravity on the running of the Standard Model constants.
29. There is no muon g-2 anomaly. The present anomaly is solely due to a miscalculation of muon g-2 because the experimental data that was used to substitute for first principles calculations of it are flawed.
30. The reason that there can't be more than three generations of fundamental fermions is that no fundamental particle can have a mean lifetime of less than the W boson as a t' or b' quark would, and fermions must come in complete generations.
31. The internal structure of the scalar mesons and axial vector mesons are basically isolated problems that will be solved one by one. There is not a single overarching cause that explains all of them. But all of them can be fully explained with existing QED and QCD, and the fundamental particles of the Standard Model. The full hadron spectrum is possible to calculate in principle from the Standard Model although this is challenging in practice and may require the development of new mathematical techniques.
32. It is not impossible that the universe flowing from our Big Bang (both before it and after it) is not all that there is, but any other universes have effects that are difficult or impossible to observe, not just as a matter of astronomy observation technology limits, but because any observable effects of other universes on our universe that have reached us at the speed of light, are so far slight.
33. The universe is not perfectly homogeneous and isotropic even at the largest observable scale, due to amplifications over time of effectively stochastic variation in the early instants after the Big Bang.
34. Big Bang nucleosynthesis is fundamentally sound, and most of the differences between theory and observation (e.g. in Lithium abundance) are due to errors in how we model post-Big Bang nucleosynthesis and our failure to find elements that are indeed out there.
35. The "Bang" of the Big Bang is due to matter-antimatter annihilation as matter tries to move forward in time from before t=0 and antimatter tries to move backward in time from after t=0.
36. The space volume of the Big Bang at t=0 is not necessary zero.
37. There was a maximum temperature and energy scale at t=0 in the Big Bang, which provides a de facto ultraviolet limit to the running of the fundamental constants of the Standard Model.
38. Newton's constant runs with energy scale in the same way that the Standard Model constants do, but the running of Newton's constant has been slight since shortly after the Big Bang.
39. There is probably a maximum mass-energy density equal to the mass per event horizon volume of the smallest possible stellar black hole, which is slightly higher than the maximum mass-energy density of the most dense possible neutron star.
40. It is possible to devise a "within the Standard Model" theory that explains why the Standard Model has the particle content, particle properties, and experimentally measured physical constants that it does in a more reductionist manner than the Standard Model plus quantum gravity, but it is not string theory, it is not supersymmetric, and it is probably not a conventional grand unified theory that fits the Standard Model into a single overarching Lie group.
BONUS:
41. The Many Worlds Hypothesis is not correct.