I don't like the "choose the religion you found" idea at all, but I would definately like the ability to choose not to found one at all even though you normally could. This could leave the appropriate religion to be founded by another civs, and/or open up the possibility for many more religions. I'm fine with limiting it to 7 in one game, I guess, but I would really like it if they were not always the same seven.
You could go Zoroastrianism if you want, just to prevent the founding of the Tao