Your boyfriend needs an attorney immediately.First, you'll need a lawyer to evaluate your boyfriends arrest and how an illegal arrest would affect his case (if at all).
Second, you'll need a lawyer to explain how federal/state cases are different, and the nature of indictments/arrest warrants.
Third, if you have been indicted then you will be arrested and set for an initial detention hearing in federal court. Bail is different in federal cases. It's not just an issue of having enough money...
If you are facing a federal criminal case you need immediate legal assistance. Texas has an exclusionary rule (CCP 38.23) for illegally obtained evidence. The federal exclusionary rule is actually less robust than the State's. Find a local criminal lawyer, one with State and Federal experience. Ask if they can assist or research this issue for you.
It is possible to plead guilty and then appeal certain issues. Most often this happens when the defense files a motion to suppress, the judge overrules it, and the defendant pleads guilty without waiving your right to appeal. This allows the defendant to avoid the cost of trial, preserve the issue for appeal, and work out a plea bargain. The State may offer a better deal for avoiding trial (especially in a busy court), and encourage the defendant to give up his right to a jury trial.
If he has a court appointed lawyer I would ask that lawyer what to expect. It is typical in many Texas counties for a criminal cases to have more than one announcement setting. But I don't take cases in Temple, so I don't know the process there. You would need a local lawyer to advise you on how many times a case is reset.
If she had a trial and she is indigent then she should have a court appointed appellate lawyer. I'd ask that attorney about how the process will work in her case. If you are not satisfied with that attorney, then you should find some local post conviction lawyers and schedule some consultations. Here is my page on how the criminal appeal process works.
Is it legal to sue you? It's not a crime to sue someone. So yes, it's legal. Will he win any money from you? That's not a question Avvo can answer. Here is what you need to, take whatever papers you have and meet with a local family lawyer. Ask them what you need to do to defend yourself in this lawsuit.
Your judge ultimately decides how many chances a father gets. If cost is a concern the Attorney General has a child support unit that may be able to help you recover past due child support. If your wife has spent $17,000 on enforcement motions then she should have a lawyer advising her and I would address this question to that attorney.
I am sorry to hear about your situation. You should meet with a local attorney who handles construction lawsuits. Most lawyers offer free consultations and you need a consultation to determine if you have a case, or if it's worth investing in a lawsuit.
You aren't going to solve anything. You need to hire the best defense lawyer you can afford immediately. You are facing very serious charges, and you can spend the rest of your life in prison if you are not careful. So start interviewing local defense lawyers immediately and hire the best lawyer you can afford.