If I may add something about sham, leveling with heal spec isn't hard or anything, it's just long as fuck
It's as Mx 420 said, you use one or two bolts, flametongue, fire totem and hp or mana totem.
The diff with the elem is obviously your damage output, but you can get a place faster in dungeons (as elem has no cc) and you can get better stuff (easier leveling) + a lot of xp in the dungeon.
It's up to the how often you go to dungeons