Rip...
The BAD Levers are nice. They take a little getting used to, but having the controls down by the grip means you don't have to shift hands after changing mags. Not much use for the civilian aspect, but if you are thinking of 3-gun or some other competition shooting, they come in handy. ( no pun intended)
Ambi safeties are easy enough to source, if you plan on swapping it yourself, YouTube is actually your friend here, as there are several videos demonstrating how this is done.
As far as a cheap red-dot, I had a SightMark Reflex on my rifle, bought it for $50 at Scheels. As far as the twist rate is concerned, A good rule of thumb is that 1:9 will stabilize bullets in the 45 to 62 grain range. It's just a mater of what you want to do with it, and testing loads of all weights until you find the money shot, so to speak.
Regarding cases, a good buddy, also former military, used to walk around downtown with his rifle on his back. He used a soft guitar case bought at any local shop for around $20-$40. While I don't recommend walking the walking around downtown part, the guitar case is a novel idea.