The rock God can't lift.

[Tiberius]

By definition, omnipotence has to be absolute, doesn't it?

It beggars belief that you can even state that. I mean, did you even look up the definition before stating it? Clearly not:

1. almighty or infinite in power, as God.
2. having very great or unlimited authority or power.

Source: http://dictionary.reference.com/browse/omnipotent

Hell, I even linked to the Wikipedia article earlier, which clearly states the multiple definitions that are used in philosophy: http://en.wikipedia.org/wiki/Omnipotence#Meanings

If God is forced to conform to logical rules, who made those rules, and what force compels even God to act within them?

Logical rules are descriptive, not prescriptive. They define reality, they don't create it.

Perhaps the simplest and most vital reason to believe in God is that there is no higher, more powerful, being to worship. The problem is, if God is subject to any limits he cannot overcome, including the limit of 'logically possible', then he cannot be the most powerful thing in existence. Logic must be more powerful than God. And, we are left to wonder where logic comes from? Is God subject to the same dumb natural forces a secularist already believes are responsible for the universe, or is there a being even higher than God?

In either case, there's no justification for worshiping Yahweh. Either he doesn't exist, or he's merely the next step up from us in a virtually infinite hierarchy (all of which themselves would suffer from the infinite regress argument; why worship any of them, either?).

This isn't about whether God exists or not. This was merely about whether the concept of omnipotence is valid. Absolute omnipotence isn't; other forms of omnipotence are.