Evolution Vs. Adaptation

The problems with your explanation is that it is no explanation at all.

We all know the direction of natural selection, but natural selection requires variations in the first place in order to select. Like in my (perhaps overstretched) example of us humans unable to become fish-like, if we just keep on breeding amongst ourselves normally, there could be a bunch of variations and it won't even make ONE of us grow fins or absorb enough oxygen dissolved in water. Something has to happen to allow mutation to happen (background factors like radiations, viruses, reproduction errors, etc...) in the first place before natural selection can jump in on the fun and say "Hey, this guy transformed the right way, I'ma just let him live."

Even if you know where you should be going, if you don't have the means to start going at all, you'll still wind up nowhere.

I don't get what you're talking about. There's variations in the first place to select in the case of humans due to mutations/sexual diversity.