If u feel comfortable riding like that, then its ok. I think the problem at least for me is to know how do u ride. If your riding style isnt the right one no matter what u change in the bike, the performance will be the same and maybe even worse if u change something, is like putting F1 tires into a suzuki swift. It would be more accurate to send a picture of u riding, then tell u what to do to fit u better then start doing the mods.
U want to change the stem, A longer one will get u in a position too "lazy" to react to changes in speed or even having problems in the curves when doing the "relieve", a lower stem might have too suffocated... actually u have to try thats all, but w/o seeing u it is hard to tell what kind of experimentation to do so far besides the stem, I would keep the same handlebar because u have a better aerodinamic position (lower) than if u were using those modolo horns ones.