#1: Since you're not doing heroics, I wouldn't worry all too much about the higher haste breakpoints. It's a nice addition, but chances are you won't be able to reach it without sacrificing the benefits of both crit and mastery in 10-man.
However, when you're certain that you'll be able to reach the 7k breakpoint, whilst retaining a relative amount of mastery (~50%) and crit (>18%), I'd say go for it.
#2: Try to get your legendary meta gem A.S.A.P.
#3: I'm pretty sure that at your iLvl – especially with the Shado-Pan trinket upgraded to 2/2 – you won't be suffering all too many mana issues. Ergo, don't socket for +320 spirit; go for something else instead, e.g. +160sp/+160crit.
That's about all I can think of ATM.
Me:
http://eu.battle.net/wow/en/characte...tanla/advanced