You haven't seen the Defense Distributed case yet? That's legal. As long as you don't print "illegal" weapons like machineguns or Title II stuff without proper NFA paperwork. They have a formal agreement with the ATF. Government finally caved on it.
Last season I hunted with a 50 cal black powder for the first time. That was a hoot. Didn't get a deer but dropped a 35 lb coyote. Much better than a 12 gauge. Big bore air rifle looks like it'd be fun for deer and coyote.
In some states, yes. In others, no. Illinois residents need a permission slip (FOID card) from the state police to own firearms. They lumped high velocity air rifles in with actual firearms. I'm sure other filthy blue states have done the same.
I'd be out of this communist shithole in the blink of an eye if I didn't have family ties here. Obama brought Chicago to Washington. That city's corruption is beyond what anyone could ever conceive. Runs the entire state into the ground.
Felon in possession. 922 violation. I forgot the subsection. If your state has a 3D printed gun law on the books, state charges as well. Maybe just state but it'll be illegal. They'll fucking regulate it like they do everything else.
As far as lifting prohibition? If it's not violent, there's a possibility the ban may be declared unconstitutional as applied but it takes a lawsuit and money to do that. There's simply no way the ban on violent felons will be lifted. Only way would be the appropriate pardon(s).