Maybe your spells are missing level 82 and 83 mobs too much. If you use improved faerie fire on the bosses you need 10% +hit or 262 hit rating to be capped. But from 0 hit rating to capped is only 14% damage or about 100-150 dps in your case.

Also I don't even spec eclipse, it's hard to get it to be useful and can only happen every 30 secs.

With your spell haste if your wrath cast time is more than 1.3 sec than it is more dps than starfire. I use starfire because I spam my dps button a little slower than most I think and can get more out of fewer, slower casts. If you use wrath you really need to be hitting that button fast for it to be worth it.

Try going into normal violet hold or something to fight lower level bosses. If you do alot more dps to them then its really just a gear issue of having low +hit and spell pen. If it doesnt go up much its probably a strat/macro issue. Let us know if you figure it out, I'm interested in how to get the most dps out of a boomkin while boxing.