Arms Spec - Expertise?

[Doeg]

The World of Warcraft Armory (http://www.wowarmory.com/character-sheet.xml?r=Haomarush&n=Doeg)

I'm hit capped, but only at 17 Expertise. I've read that it's best to spec into Weapon Mastery to reach 6.5% dodge reduction, but I don't know where to take the points from. Should I remove them from Improved Execute, Improved Mortal Strike, or something else? Would it be best to leave my spec as it is and use some expertise gems or enchants to hit the cap?

I realize some of my gems aren't ideal, but I don't want to spend too much gold on gems for sub-par gear, as I'm in a guild of players with superior gear who can help me get upgrades.

Also, about how much DPS should I be doing in raids with my current gear?

[MellvarTank]

I am not as familiar with arms, but from what I've read Improved Execute is not really a required talent now that it is capped at 35 rage (max). I would recommend that if you want to spec into Weapon Mastery you drop that.

Other than that I always try to hit expertise cap and hit cap, expertise being the harder to get to of those two. (Sorry I can't check out the armory, I'm at work with limited interwebz.)