Ahey,
In the very least, everyone should have full triumph gear (cuz it's so easy to get) and everything that suits your class from heroics (cuz they are so easy to grind).
That's... a bit misplaced. If you look at my gear level, it's probably way under other priests out there. I have a couple of pieces of 213 (T7.5) and several pieces of 219 (T8). I'm only now breaking +3k SP fully raid-buffed on Holy.
I don't grind Heroics. Never did. I bought at most one single piece of Triumph gear, never having had enough badges for more. I have a total of about 40 Frost badges. And yet, one way or another, people still consider me a very solid and dependable healer.
Yes, gear is important, but it's not the be-all-end-all of high end raiding. Knowing your class well is much more important. Learning to replace purple fever with a constructive attitude, like, say, Astroid's, is a step in the right direction. Half an hour of research trumps ten hours of gear/badge/rep grind.
The one single most important thing, however, is to realize that "my rotation" is definitely the right start, but if you're stopping there, you're cripling yourself. You need to know how to work your class in as many different groups as possible. You need to know what to do in a given fight if, say, you're the only melee DPS in the group, or the only caster, or the only CC-capable character, and you need to know what to do if you're one among many. Chances are it's not going to be the same exact thing.
These are the sort of instincts that only come with reading as many sites out there as possible, and then seeing it work in actual 10- and 25-man raids. If you really want to learn your class in depth, go spend time reading and talking with people, then go PUG basic raids, like Ulduar or even Naxx, and experiment.
Gear is not a substitute for hours spent raiding.
Cheers,
J.