Re:too old to start mma at 40?
Not at all mate. I started at 30 and it was the best thing I ever did.
My mate who trains with me is 48 and he started the same time as me. He loves it and has lost 2 stone!!
Be careful though. MMA is hard on the body, especially the first few months where you are getting used to moving, falling and using your bodyweight, so take it easy.
It may be worth separating up the BJJ and Muay thai elements for the first few month just to get some fundamentals and learn how to move.
Either way, take it slow, warm up well and you will love it!
"You gotta eat big to be big!"
6'6"- 270lbs - 19.5" arm