As far as group 2 goes you're not going to make it very far with your tank being you're healer. Only reason paladins are able to tank for extended peroids of time is because of spiritual attunement which does not proc off of their own heals not to mention the fact that their heals are going to be light anyways without the +Healing gear and you'd be losing aggro building time while casting a heal on yourself.

Also Shamans have healing totem + chain heal which I see a few times you listed groups with shamans as having no group heal. It may not be as good as priest group heals but it's worked effective enough for me.

Lastly if you've been lurking around the forums for awhile I'm sure you'll most likely expect most people to tell you that 5x shamans or 1x pally 4x shamans is "the best" set-up. Given that you didn't list those or any variation of them I'm assuming you'd like to go against the norm, which is commendable, in which case I'd say that most groups with the basic Tank,3x DPS, Healer set-up can probably handle heroics given enough time, effort, and determination.