Welcome to the forums.
Removing rollers and cutting the shoes is done to improve the holeshot.
Some like removing the rollers, some don't. I'd leave them alone and let the kid ride.
You don't need springs.
I do recommend the removal of the clutchs to clean. Check for flat spots on the rollers and grooves/gouges on the variator and the roller plate.
Rear clutch you check for bad bearings and lightly sand the contact patch on the shoes.
A good carb cleaning always seems helpful.
Ride the snot out of it. Need anything, we'll all help. Lots of good ppl in here.
2000 GNC 5N\
2001 GNC 9N \ 40+ class
2004 GNC 9N /
2014 rock crusher "GO tortoise GO!"
2016 Byrd Rooster
Father of the "11" time National champion,and worlds fastest woman ATV racer
A few fast LT80's
250R~300cc's
300ex
350 Rancher
Kymco Mongoose
Survivor of the 12 Hours of ATV America 04 and 05