I've been known to ask healers to, at the very least, toss DoTs up on stuff. I'm all for you tossing around a little damage, so long as I don't fall down and you don't ever say "Shit" mid run do what you do. If your making the run faster more power to you. Of course with people I don't know I can get a little sketchy if my hp falls below 50%, but for the most part I won't tweak about it if it's fixed quickly, and if it's a clear pattern where I'm always brought back from 50% w/o needing to comment I'm happy.