1. Rank 8 gear is 'the best' due to more atk/def lvl bonuses and weapons. Stats are random.
Dragon is end game for pve imo
As for accessories, Cube neck, Warsong belt, Ascended dragon cape (nw forges, def cape)/Supreme cape (it's the old dominance cape, upgrade in nw forges, atk cape), Dragon headgear, Dragon rings, r8 ring upgraded in nw forges
2. Demonic gear + warsong crystals
3. Cultivation gives you access to celestial/morai/primal skills
4. There are 3 fairy stages (you can do only the first fairy and buy 3rd one from boutique)
5. Bosses in culti instances drop skills, people sell them for cheap via auction house/catshops, you can craft them using old book pages etc
6. Fairy or genie? Fairy is a cultivation thing, genie is your life saving team mate.