1 – once you’re at your location and have taken the bikes off, do you remove the bike rack and lock it in the car for safe keeping while you’re cycling?
No, I just leave mine locked on the towbar. The mechanism that clamps it has a lock built in, although I guess it would be quite easy to break.
2 – has anyone figured out a way to add a bluetooth type ir other camera to the rack to help with reversing?
No, ours is on a van but I’ve never found it too much of a problem. My wife has reversed it forcefully into a tree and other such objects so it’s looking a bit battered now. The actual rack can move a bit on the hitch (unlss you over clamp it) so it does help it resist the odd whack.