26 Expertise is where you rule out dodge and you can no longer be dodged; after that it's still slighty beneficial for parry. Iirc.
As for hit, I think 8% is indeed the melee cap. Our spell cap should be around 18% depending on if you're dragging along other classes with hit buffs - You generally don't gear to reach the spell cap, though (regardless of whether you're playing DPS, tank or PvP). Aim for 8%ish as DPS and you should be cool. As tank, cap out resilience first and then go for the 8% hit.