Nothing wrong with picking up Desperate Prayer.
Having only 2/3 points in Twin Disciples on the other hand screams baddy, I'd reject you on that alone
Your combat regen is a bit low for holy going into FL heroics, a non-spirit neck in your gear isn't a good idea. I'd recommend the Tsunami deck, it's great for Holy even at the FL level.
Raid buffed, you're at 14.55% haste and Mastery heavy which is fine in my book but rolling with two resto druids, haste heavy may be better. But considering your regen, that isn't optimal.
The overall number of times you've used Binding Heal and Renew are far too low.
Most importantly, your highest HPS spike on all bosses barely hit 10,000 which is quite low for holy. You should be nailing double that during your HPS spikes, especially in 25 man.