I'm going to go ahead and second everything he said minus the whole playing for a year thing, which I have not.
That being said, I've been playing for a few months now and haven't experienced this issue.
The classes that have a "free" heal, as you said, also have drastically more limited resource pools, and much reduced burst potential.
It's a trade off, and it's intentional.
If Sorcs could do everything the other healers could do, and also have infinite force, and also have a free spammable heal, there would be no reason to heal on anything but a sorc.
Different classes are different.
Welcome to MMOs.