Regarding your wheels, not all "split rims" are bad. The ones that come apart as two pieces are the killers. Search on "split rims" at the top of this page and you will get more info regarding what is safe and what is not. You can start with this thread, it has some pictures you should perhaps see:
https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=351534&page=allRegarding the two speed, I don't see how you could delete it and still retain capacity. Unless maybe you increased the engine size in a big way. It all depends on where you really want to go, you should decide for certain before you start changing things or you will do many things twice.
