Yeah don't chamber to the side. That wont help anything, just waste movement. Either do it tkd or do it Muay Thai. I think you probably need a firm foundation in one of these arts before you learn both because you will get really mixed up. This kind of happened to me even though I had a pure 6 years of tkd (but I was a kid). I'm well aware of the brain risks. I had a craniotomy done June last year and ive had to be very careful with what I do. I still don't think I'm technically allowed to get hit in the head for sparring, so I avoid it.