It should be feasible. If you feel like its taking too to get into keys, do your own 
thats my advice.
I dont recall a single fight where I felt like Hpal wasn’t good enough, hardest probably would be 3rd Boss of HOI (its a tough fight on every healer either way) and probably Deios (last of uldaman), just for the fact that if you are running Virtue like me, you well really have to watch your mana and infusions (specially on rewind time/suck pools phase) or you can get close to the end and run out of mana.
As a final note, wish you luck. Sooner or later they will have to address the spec, considering how many people is unhappy with the state of hpal. If you manage the get a grasp for the spec now at its hardest, I guarantee you when that happens, everything after that will feel like a breeze.