The lower's fine, probably
Painted mags are fine, as long as they're the color scheme of your surroundings
I've seen US security teams use 40 rounders, but I'd stick to the 30s for mag compatibility
>That upper
You wasted your money
"Sabre" and other titles PSA give their products are still from PSA
Sell the upper to some other poor fool and lurk /arg/
Here's their pastebin: https://rentry.org/sa6c4m
>That optic
on an 11.5"? Why? Just use a 1st gen Romeo 5 and upgrade to a T2 when your budget permits
Above all else; GET OUT TO THE RANGE WITH IT