if im doing instances under level 30 and i have a DPS role because i cant tank bc my armor isnt good enough could i be effective at DPS as a more mele type shaman? at this low level could i be good dps with spells and mele?

Shaman can't tank. They can heal, or do dps. It has nothing to do with your armor, you just can't tank. There is no shaman tank spec.

Your mainly going to be using spells no matter which spec you choose.

To my knowledge, shamans cant tank. They can DPS and heal, and depending on what spec your are, RESTO for heals, Elemental Combat for Casting, and also Enhancement for casting :P I dont think they are good melee DPS'

Enhancement is a melee dps spec for shaman. Yes, you'll probably still be casting spells, but you want to be in melee range for your dual wield and the lava lash/stormstrike/primal strike. So, yes, you can be effective at melee dps if you go enhancement.

P.S. All you people who said enhancement is a caster spec are idiots

Thats Shamtastic

Ever since they added primal strike to the shamans list of talents, the enhancement spec sees more use in the lower levels. You can be effective either way at DPS with either enhancement or elemental. Try them both out and decide what you like.