Yes. Persistent contrails - i.e. aviation-induced cirrus clouds which spread in supersaturated air layers - are indeed bad for the climate, but often their effect is ignored as hard to quantify, while the simpler small effect of short-lived contrails is conveniently cited instead.
Also, while all high clouds have a warming effect by reflecting infra-red radiation back to earth, there can also be a cooling effect due to reflecting solar radiation, which is greater when the angle of the sun is low. So the net effect is warming in the middle of the day and at night, but cooling in morning and evening.

Yes. Kinda, just a little regulation could reduce them a lot.

But here's the thing. Congress does not give a shit about the climate. They will never pass anything like you're suggesting because they're for sale. Only a major structural change that eliminates coercion/bribery from regulatory votes will work.

Congress as we know it fighting climate change is about as realistic as unicorns and Bigfoot.