Honestly I think merc healing is pretty OP and fine just the way it is

Never had a problem... all you really have to do is group with people while you're leveling. After running with people that are good, just ask if you can put them on your friends list. Most won't have a problem with that. Then when looking to do a FP just whisper them if they want to start a group with you. Unless they were tank/heals besties playing together more than likely they've been just waiting to see someone spam a certain FP. Run as much as you can and get in good with as many tanks and heals as you can... basically by just showing that you know how to play your role. Also helps if you're social during the group and make it fun. I think bioware did a decent job of keeping the game social: social points, heroic quests, FPs... you should be grouping up almost every level. And even when you hit 50, you should be doing daily heroics and what not building up your social base even more. The whole point of an mmorpg is to be social... take some initiative if you find yourself getting bored. Most people are just waiting for someone to start a group.