1. Focus on EH, the only fights that really favor avoidance is Saurfang and the Gunship Battle. For your enchants I would 16 defense on your cloak to 225 armor, your chest enchant to 275 health and your chest gem to 30 stamina, bracer gems to 30 stamina, gun gem to 30 stamina, glove to 240 armor and change one Brewfest trinket to the Black Heart. If you are only doing VoA and heroics than you should be fine.
2. Your spec is fine if you are in heroics but once you get into raiding I recommend this spec Talent Calculator - World of Warcraft
3. For casters use Shield Bash and Heroic Throw, both those abilities will silence the casters allowing you to move them with the melee.
When a mob peels away and your taunt is not up you could try Heroic Throw and if thats not up try this macro from Tankingtips The Art of Warbringer - Warriors - TankingTips.com , it will make it so that if you target an enemy it will charge, if charge isn't up it will intercept and if you target a friendly target and use it it will intervene.
The rage starved issue there isn't much you can do about that, try taunt early so you can get a few hits on you.