Legal Question in Family Law in Texas

Re: my 16 yr old son wants to come back and live with me.

There are as many complications possible as there are grains of sand on the beach. You have retained an attorney, who has quoted you a very fair price on a retainer for a very difficult situation. You should be placing your trust in that lawyer and asking him/her about the issues you will face. If you don't have that kind of trust or communication, consider getting another lawyer. Custody cases, even with 16 year olds who choose that parent, have a nasty habit of getting difficult and complicated.