JackOKnives:
Super important question though: since we've lost a bunch of heroes recently, do Rangers also dramatically fall over and then explode when defeated, or is this more of a "blasted out of your transformation" kind of affair?
The latter. Since the suits are made of crystal, pieces break off for dramatic effect. So, when defeated, it shatters.
JackOKnives:
Oh, right, if the PC's are being brought on as a new team, should I expect a pretty tight theme shared among them?
This is one of those genre-breaking moments I mentioned. There is no theme like animals, dinosaurs, cars or the like. Instead, the shared theme is martial arts and ki.