Backtagging
Always, though I do tend to slow down significantly after a month.
Threadhopping
Yes for Network-type threads; ask first for prose/log/action.
Offensive Subjects
None. I'm generally okay with any potentially offensive material coming up in IC interactions, provided it's actually IC and not a reflection of OOC attitudes.
Warnings
Jeff engages in semi-regular recreational drug use (marijuana), so it may come up in scenes. It's mostly to self-medicate anxiety issues, and he's generally a functional stoner. I'll always warn for it if he's high in a top-level, and I'll steer clear of references to it when interacting with somebody who'd prefer to avoid such content!
He also has a little bit of a Dark PastTM from his early 20s, but it isn't likely to come up in most scenes. Said Dark PastTM includes demon-induced psychological torture (hallucinations, fugue blackouts, intrusive thoughts), heavy drug and alcohol use, and a brief stay at an inpatient recovery program. I'll always use warnings in the subject line if a tag starts to go into this stuff.