I don't know much about SM, so I can only answer those which I can answer.
B) Sometimes my droids don't fire at the end of the turn despite my heat and energy levels being fine. What gives?
is the drone require ammo, bullets or missiles and such? when I was still playing some drones need bullets and missiles, and without enough ammo they won't work.
C) How does one obtain Tokens?
tokens can be purchased (using real money)
D) Does excessive heat damage a mech?
no, it only make ur mech unable to do anything for a turn or two, or maybe more (depends on how overheat'd u are).