Part A
1. I'd agree.
2. For a hydrogen-like atom, the angular part of the wavefunction is only directly dependent upon l and m for the stationary states. Although obviously for the overall state, the value of l and thus m are restricted by the value of n.
3. For a hydrogen (or any one electron, one nucleus system) without making relativistic, spin-orbit coupling and other corrections to the orbitals (so in their simplest form) the energy of the orbitals only depend on the n principal quantum number. The energy formula is the same as that predicted by the Bohr atom model. However, things get more fiddly if you break the symmetry of the potential (i.e. by adding another electron in the system) or when you start accounting for relativistic effects and spin-orbit coupling. The latter two effects, for hydrogen-like atoms are typically quite small in comparison with the divisions between the energies of different principal quantum numbers (it's in the order of something like 1000 times smaller). However, for hydrogen-like atoms with greater nuclear charge (e.g. He+ or Li 2+), relativistic and S-O coupling effects become more pronounced.
4. My guess is as good as yours.
Part B
1. The wave function must be continuous, and their gradients must also be continuous. One possible justification is that the kinetic energy is related to the curvature of the wave function, if the wave function were not continuous, it would have have infinite curvature, which would result in infinite speed etc. popping up which is problematic at best.
2. The wave function must be single valued, becuase it corresponds to a probability amplitude, thus as you said, there can only be a single probability of finding something somewhere.
3. The wave function must be normalisable; that means that its square modulus must have a finite integral over all space. This is related to the probability interpretation of the wavefunction- there must be a finite probability of finding the particle somewhere.
4. You could split 1. into continuous wave function and continuous derivative (gradient).
I'm afraid I can't help you with part C, not really my area of expertise, but I hope this helps. (: