You can do the lvl 55 HM fairly comfortably with the 148 gear from the lvl 50 FPs. Also, most of the fights have minimal mechanics to deal with. Usually just not standing in stupid stuff and only a couple bosses require any urgent dispelling. Just 5 stacks of Laser and Crushing Affliction off the top of my head.
The "bad" players won't be bad forever (hopefully). 1 issue here is the agonizingly long queue times. Starting off as DPS is the safest option for new player, however they must wait an hour or so in the queue line. Healers get medium queue times, sometimes almost instant if they are lucky. A tank can get an instant queue, gear up in a day or two and then have no incentive to do FP again.
Possible solutions: Cross Realm Group FInder or more incentive to queue.
2 comms per boss is pretty measly.