Is there any point by taking this talent if im already 10 exp above the cap and hit caped? Im not missing any spells so it seems kinda waste of talents, or am i wrong?
....if you're capped, the points are better off being spent elsewhere, though unless you already have BiS gear, which you don't, I would suggest keeping it, because you'll end up giving up some expertise gear for something that has higher dps but no expertise stat.
The only time to spec out of a +expertise or +hit talent is when you're in the best gear possible, so you don't have to worry about losing your cap.
If we're only talkin about cat dps: Absolutely true. You shouldn't miss any attacks if you are hit&exp-capped so you shouldn't miss with your attacks.
Though keep in mind, that expertise cap is significantly higher if you're attacking from the front. There are some bosses where you cannot attack from behind all the time (for example: Kologarn, Thaddius), where those two points would definately add to your DPS.
Though the best idea would probably be to take some gear with less expertise and more offensive stats.
TLDR: On Patchwerk-style fights: 2 worthless points, on Kologarn: Important points.
Agreed. If you shed some expertise from gear and replace it with more dps-oriented stats, then it's worth taking. Otherwise, there are better places to spend extra points (FA, iLotP, imp mangle, whatever you're lacking now). I wouldn't spec into expertise purely for Kologarn, being one fight of 14.