A: I'm going to answer my own question after contacting HTC and Sprint. Here are my options:
1) On-site phone exchange - $19. They send me a mailer, I put my phone in, once they get it they send me a replacement. Likely a refurb.
2) Service Center - I mail it to the service center, they repair it and bill me. They estimated for this issue it would be $120. Benefit, I keep my own phone, although I'm sure they wipe it as part of the checklist.
3) Take it to Sprint, who will do a repair or replacement for $75.
So the risk with #1 and #3, is you will likely get a refurb, which may have the purple tint issue, wear and tear, etc. My luck has been *mostly* good with refubs, but a few years back when I was on T-Mobile, I one time had to get 3 different phones before I got a refurb that was fully functional. No idea how HTC or Sprint's QC is on refurbs.
#2 is the most expensive, but at least I will get my own phone back which I know has had the camera sensor replaced under warranty already and which has already been SIM unlocked.