Best way to find out, retain a personal injury lawyer to advise you. Too many unknown variables to give a definitive answer. Most of us offer free consultations and work on a contingency fee basis. Make some calls and be sure to educate yourself on the particular facts of your claim(s) before doing anything with the insurance company.
In Florida, yes, owners of motor vehicles are held liable for damages sustained by the negligent operation of the same, even if you weren't driving. Be sure you contact your insurance carrier and place them on notice.
Patience. These things take time, unfortunately more time than 19 years ago when I first started. Yes, typically money is held back to cover unpaid bills/LOP's/liens when BI is settled and UIM remains. Just keep an open line of communication between you and your attorney. He already got the BI limits from the sounds it prior to reaching MMI.
As you were an excluded driver from the sounds of it I would be more concerned about the other driver/passenger coming after you for their injuries. Do yourself a favor, and other drivers here in Florida, go get insurance or get off the road.
Call some personal injury attorneys. Maybe it's something, maybe it turns out to be nothing. Too early to tell. Best advice is not to talk to the grocery store or their carrier until you have spoken with counsel.
Your attorney is the best one to seek advice from. That being said I can't preach about buying uninsured motorist coverage enough. You need it in this state. It sounds like there was only $25K of available BI coverage. At least they had that. All too often I can't do anything for my client b/c there is no BI coverage and no UIM.
You will want to find a good products liability attorney. However, that being said, it may not be easy if the damages are not great enough to justify their expense and time. Don't give up and keep calling around.