Well first off and welcome to the site!! You are in the right place.

I can't really help you on any of those questions except study your builder VERY carefully. Been there done that and still have leaks. If I would have found this site a year earlier my pond would be SOOOO different today. You have one of the best builders in Texas. He is a member here and maybe will chime in also. There are many here that do what you are proposing so the info will be coming. You might try searching out growing forage and such.