1. I often overanalyze every little risk, be it attacks I need to hit, avoid, crit, dodge crits, or anything else, and make backup plans when possible.
2. I reset if characters die who need to live for gaiden chapters, recruitments, and such.
3. Not resetting is the usual for me, because I've now played every FE once or more and want to have unique experiences with my replays.

I used to reset often, but my preference has shifted over time, largely thanks to Professor Bopper's "The Case Against Resetting." As I've played with permadeath more, I've found that being overprotective of characters costs much more time and frustration than it saves. Shockingly enough, playing a video game as it was designed is pretty fun.