1. yes go for duals, probably java serv so cd don't work as it should.
2. for mass pvp/solo pvp if you have full buff go +4str+4con -8dex. Oly is a bit diffrent story...
3. skill dmg.
4. no berks, with g.shield.
5. passiv P.Def it's sh1t. Make Duel Might passive(it's pvp p.atack so you need it).