Alba is much more solid than Coentrao, Coentrao and I just never got along!
I'd switch Masch & Pepe, get Alba for LM, er... LB

and Jaoa Perreira for RB.
Essien is good, you have a nice combo of M/M, M/H and H/H CM's in there, but you could get Song, put him at CCM and put Alonso out on the right where he can distrbute down the wing to Di Maria as well as covering a bit more for your chosen RB.
Also, on Valdes, heard good & bad things, so really your call.
If you have difficulties or find yourself needing more men in the middle during a game, get Villa for your bench, switch to 4321, play Villa at LF and Iniesta behind him
