Sorry for the late answer; for this kind of questions you really should visit the official forums or the subreddit of rift.
But yes, people are playing Rift (can only speak for EU shards). You can do shard-hopping every time and do events etc there.
You can also transfer to another shard (server) for free every week.
Every class has one heal specc (only cleric has 3, iirc).
Rogues and Warriors can heal, too, but you need the Dream Souls from the shop.
Mages and clerics have heal souls since the beginning of rift.