in the past, I've always approached Hidden Valley with Veronica. However, I recently found out that if you approach alone, they slap a slave collar on you to force you to do their quests. I was thinking of going solo but this would mean I would see what bastards they are at this chapter of the BoS. That puts me in a bit of a situation. Once collared I won't want to do their quests simply on principle. Does the collar eventually blow?

The other thing I was thinking is that I could get collared, and then do DM, which would strip my inventory and swap the BoS collar for Elijah's. Then, after DM, I just wouldn't pick the collar back up.

Also, this brings us to the endgame. Even after everything, I don't want to wipe them out, but I do want to gimp them as much as possible, hopefully avoiding their essentially becoming bandits on the I-15 hijacking people's tech. Is there a way to do this with an independent ending?

The collar does blow up if you leave a certain area. The area directly around Hidden Valley.

I dont think its possible to get into dead money without it going off

And no, there really isnt anything you can do to prevent them from essentially becoming bandits in a indipendant ending without blowing them up.