1. Yes, only important noncombats. Agility, slayer, thieving, construction. Faster run energy is important and obstacles in wilderness, slayer for certain equipment, thieving shortcuts, construction for a decked out house.
2. Quests are 100% important to me but I say that as a quester. I would never ever buy or create an account that didn't have perfectly quested stats. My current 1 def pure has 198 quest points right now and still not done.
3. Only ardy easy diary, wilderness ones, and varrock easy. Varrock body is best 1 def body slot.
4. Yes and no. Graceful is nice to have but not necessary. Skilling outfits I dont give a shit about for pures. HOWEVER, minigame/quest outfits are prime. C wars gear, ghostly, etc.