2. No
3. Personal decision.
5. Dark
6. Good healers are hard to come by and necessary, while other roles aren't strictly required. Buffs and debuffs have flexibility, but healing is mandatory. Sol and Amaterasu also have very useful buffs/debuffs.
7. Up to you. I'm waiting for the next Fire event for the new water SR kamihime.
8. Yes
9. Jorg buff. I often run with 7k HP.