poland_jack,
Welcome to the forum. As you have observed, there's lots of good info here.
On your question, it is generaly recommended that the structure be in the 4 to 6 foot depth range for bass ponds. Pushing the whole live oak tree is a good thing. It should provide great structure for a long time to come. In my experience, the best structure is the natural kind. Nothing works for me as well as trees/brush.
