I'm not a lawyer, but as the AR15 is designed to be broken in the middle, unless you were caught red handed with the Other NON NFA upper on the NFA AR lower and vice versa, you have done nothing wrong and this should not be a concern. I would go as far as saying that if you store them normally broken in half, even having the 2 sets in a dismantled state in the same safe should not be an issue....
For handgun, earmuffs with the highest noise reduction ratio I can find. Howard Leigh electronic if I need to hear range commands, otherwise I’m fine with passive. Foam plugs for rifle and shotgun, as earmuffs keep your face off of the stock.
Glasses always! I’ve yet to find plastic ones I really like, but it seems impossible to find any made with safety glass anymore. I love my old Bushnells.
For long guns I just use 3m ear plugs from Home depot because muffs get in the way of my cheek weild. Handguns I have a set of the Howard leight ear muffs.
I only wear eye pro when at a range that requires them. Just some cheap ones nothing special.
Current glasses are pair of Wiley-X that I retired from motorcycle duty when the foam pad wore out. I have a spare in my range bag and another spare in my truck. Ear pro is Howard Leighton electronic. I have a pair of foam in my truck also.
The Decibullz did not work well for me, did not block enough and I had problems with my hearing for over a month after I used them for a day at an outdoor range even. The muffs do get uncomfortable after awhile especially in the summer; but worth it for me vs hearing problems.