Hobo Elf
Arcane
If you replay a game then that falls under metagaming since you're approaching the game with knowledge that the game hasn't imparted on you yet.
Only if you abuse your knowledge. In Morrowind, I never went out of my way to search for powerful items.
There's no way not to abuse your knowledge short of getting amnesia and forgetting everything. Everything you do will be done better and more efficiently in replays and that's simply because you have meta knowledge from the previous playthrough. You can avoid beelining for the powerful loot but as I mentioned you'll still be playing the game better and not like a new person simply because of the things you know.