When you say Tank you have to think about two things:

Damage Mitigation
Threat

You seem to be focused on whether an Enhancement shammy can do the first -- even if it could, it can't do the second. Enhancement shaman have 0 talents, 0 skills, 0 abilities to create threat even SUB par of Warriors/Druids/Paladins. This is because Blizzard from day one has not wanted Shaman to serve as main tanks for anything except solo work. It is meant to be an offensive hybrid (shocks, offensive totems, etc).

When you create no threat, you are not a tank, you cannot keep a mob on you for very long. Your Elemental Lightning Bolts will absolutely rape threat meters compared to an equally geared enhancement with windfury. Hence the bouncing/kiting problems.

I highly recommend you listen to the advice given above, I won't waste my time repeating it.