I am glad to hear that you, your house, and family are safe! The thought of a fire like that terrifies me. I am sorry to hear about the damage you had and hope the insurance company is reasonable and hassle free. With that being said take pictures of everything! If it comes to a fight, then photos will help. That fire came so close, truly scary.
How much physical damage is there to the tractor? Can you post pictures of it? I would disconnect the battery for now, if there is a short due to burnt wiring you don't want it starting another fire. I would check the air cleaner and make sure that it is clean and the filter housing has no obstructions. I would then check the hose running from the cleaner to the engine for any holes, don't want to suck any of the ash that you have floating around. Once you post some pictures of the tractor we might have some more advice.
I cannot imagine the stress your dealing with given the situation your in.