As far as training and being fast goes :-). Weight is an issue (lost 125 myself and fighting to drop another 20). But there is a genetic lottery involved, we may never be fast, we just may not have the raw material. Then there is according to the cyclists training bible 5-7 years of training to reach the pinnacle of the natural ability we do have :-).

A wheel upgrade might be the best bang for your buck right now, removing 200g or more of rotating weight in my experience sure FEELS a heck of a lot faster :-)