You cannot shoot a thief merely because he is in your garage. You must be under some real threat of danger to yourself or family that justifies use of a gun. Forget about the "citizens' arrest" stuff. Planning to have your wife videotape the next break-in does not leave the impression that you are in fear for your or her well-being. Secure your home and put up video cameras. It almost seems like you are "looking for trouble".
Hire a private attorney ASAP if you can afford one. PDs are usually not appointed until after arraignment at which you should plead "not guilty" and say no more at all about the charges or your defense., other than to explain the financial circumstances entitling you to PD representation.
This does not seem like the type of injury case or settlement where 50% of the value belongs to the uninjured spouse. Ask for whatever you want. %0% would be a starting off point for negotiating purposes. Your rights only concern the time period you lived together a husband and wife, unless the accident somehow caused the marital split.