I still LOVE boxing. I am a 4 ele shammy team and they are pretty good in BGs.

Leveling up via questing is decent. There aren't a massive amount of collection quests, and the first zone Mount Hyjal gets you to at least lvl 82. Another option is leveling up via battlegrounds. If you have full wrathful from lvl 80, you will dominate lvl 82 onwards.

I can't talk about heroics as I don't box them, but they are harder than wrath heroics, easily harder.