Fridge Brilliance: In "Reinforcements from the Future", one scene has Ransik (the villain of Power Rangers: Time Force) interrupting a powerful incantation by three Mutant-Orgs to try to defeat them. It doesn't completely work, but it has the side effect of nullifying the Mut-Orgs' mutant powers. Guess what happens to the half-mutant, half-human Ransik later?
Fridge Horror: The mutants are supposed to be frozen, some of them for life sentences. One of them mentions that he has had two years to think while frozen. Just imagine a what a longer sentence would do.
This and the fact that, either way, the mutants they fight are citizens and not any kind of inherently evil force are likely why this is a strictly no killing season.
There's also the fact that, as kindly pointed out by Linkara, the Mutants are probably human beings with hideous mutations. (Thanks Linkara)
Fridge Logic: If Alex is Wes's descendant, then why does he not seem to care about his supposedly inevitable death in the finale? Wouldn't that erase him from existence?
It's implied Alex isn't a direct descendant of Wes. Rather, he's descended from a relative of Wes (a cousin or something along those lines).