Does it need a new BCM?

One day my car would not start. I tried several times. Took the battery out had it tested and charged put it in and the aftermarket Code Alarm that has been on the car 24 years went nuts. Had to leave the battery disconnected. The alarm was removed by a knowledgeable locksmith. Everything was working fine. Periodically it would have issues including not recognizing the key fob, no power windows or locks, no radio, etc. I would try and reprogram the security system and things would work for a while. One day I try to start it and there's no crank. I tested all the fuses and the 10 amp fuse for the ignition system was blown and it blew immediately when I put another one in. I purchased and installed a new steering column theft deterrent lock. Also I installed a new battery. The fuse no longer blows but still no crank. I tried reprogramming the security system again and now it starts and I have locks, windows, radio etc. I have not had any starting issues for a week. But after this last reprogramming, the airbag light stays on and a chime goes off immediately when I put on a turn signal. My locksmith friend said it might be the body control module going bad. Any thoughts on this problem?