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?
In the season finale, Ransik is shown the error of his ways by his daughter Nadira and her newfound love for humankind. It's Trip who, accidentally or not, shows her not all humans are evil in the first place. In a way, it's Trip, the Innocent Alien who believed he wasn't as good as his Ranger peers, who was the first to trust Nadira despite her betraying him before, who saved the fate of the world as we know it.
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).
He wouldn't even need that - so long as Time Force, able to travel through time, exists, they could collect his DNA at any point. In true paradoxical form, they could even approach him after he became a Power Ranger and saved the world, but be doing this before the other Time Force Rangers in the future went back in time and oh I've gone cross-eyed.