One 5 Blues : Using nuke seems mandatory indeed because not enough destructive skills. Your solution with flooding a chain then nuke and block near the exit does work, though it could certainly save more than one with a little tweaking and luck.
Maybe I'll work a little more on that, but the number of ways to reach the exit is so big that I'm scared I cannot counter them all.

Intended solution uses the whole level, and control the lemmings so that it is quite impossible to miss the nuke part.

Eon2, Eon5 - look intended for me now
Neo1 - probably intended? since you said the intended solution is counter intuitive and I made the turn-around point farther and save more time as a result.
One2 - looks intended
One5 - another nuke solution.. I'm pretty sure the intended solution has some kind of nuke interaction in it to compensate the lack of destructive skills, but I'm not sure if this is the one you intended.

a skill adder, it will change any lemming that passes through it into that skill.

Eon 2 Trust Your Lucky Star ? Nice trick to let them compress and clear 2 bars at once with a single miner. I'd rather player to bash through the last structure, then figure out how to save the climber. You can do this even with saving a skill for the talisman.
So I just moved the trap one bar to the right to prevent your solution.

Eon 5 Four Shruggers Real Backroute there, you're not supposed to reach exit using a single Lem ! Interaction is better so I worked on the chains again to prevent using the 4 bridges with the upmost lemming to exit on his own.

Neo 1 One Hot Minute Backroute again, not supposed to be able to bomb the way through the E by going the upper route. I put the star some pixels higher to prevent this.

One 2 Aquarium Deception Oh no ! Saving 70 Lems here ! My bad, going above the shredders was supposed to be a splat fall. Level is way too easy like this, I set the splat again.

One 3 Clappy Clapple First solution is intended. Second is very fine too though more tricky. It again shows how Release Rate and compressing lemmings can be powerful in this game, good job ! Level did not change.

One 5 Blues Nice solution too, you went through very little pixel and hard timing to get there I'd say ! Though I will consider it a backroute as you dont use most of the level and it looks like you got quite lucky at the end that the 2 survivors were close enough to reach exit like you did.
I made little change here again, can you find intended ? It is more straightforward and a bit easier to execute I think, you're not very far actually.