A stock axle will be better, a raptor or blaster axle is narrower and will do even better. What tires are you running? Pro wedge or maxxis 4-snow will do well on the sand.
There is some 15 year old rookies that show up on here and talk junk but I just ignore them. This site does not have as many as others out there and there is good knowledge still found here. Maybe you will be back, I hate to see anyone leave that contributes info and pictures of projects they do.
Why mod your shee if a stock one will win from 0-60, most races are short anyway. Don't you mod for the purpose of more acceleration. I don't beleive something just because it is on tv.
When I still had front fenders my left pipe melted the plastic where it touched, but it just melted until it did not contact anymore. No real harm was done.
LA sleeve makes sleeves for most models. Probably any machine shop can install the sleeves but it gets exspensive. Unless you have port work done allready it might be cheaper to buy some used cylinders.
Eigther cut them or your backup pair. I debated on it for a while and finally did it and like it a lot better. It looks more like a race quad without them.