If your son is over 18 and is a convicted felon, he is looking at 3 years minimum if he was in actual possession of the firearm. Otherwise, the Grand Theft is punishable by 5 years prison, the burglary by 15 years prison, and the FA charge by 15 years prison. Get a lawyer.
It is you to tell with the facts given. GT is 5 years, 15 for the Dwelling Burglary, 1 year for the possession. 1 year on the VOP for possession. The possession of. A firearm...it depends, as Mr. Hornsby said if he is a convicted felon, then he is looking at a max of 15 years, 3 minimum mandatory if he actually possessed. If he is not a convicted felon, then it may be CCF, which is a third degree felony. But watch out, they could file a Burglary while armed, which is a First Degree felony.
Sounds like there may be addiction issues. Probation extension may be an option but with his history, drug tests should be expected. That could result in further probation violations which add up fast when using the florida sentencing guidelines. Next thing you know your son will be scoring mandatory prison. Ask your attorney to ask judge for an alcohol and drug evaluation. Then you will find out if more supervision is realistic. Your son will be desperate and want to just get out but tell him to be patient and have his attorney really talk to him to see if he can complete probation.
This is only general advice based on our reading of your question. Further investigation into your case is necessary to pinpoint the best possible approach for your specific case. Your case may be winnable or it may be better resolved through a plea. Further information and client consultation are critical to making those decisions. Please do not act on our speculative answers without consulting a licensed attorney with experience in this area of the law.