Rolling

My 04 Summit exhibits the 'point and shoot' clutching that is famous for skidoos. Really crappy backshifting in DEEP snow and when climbing for long periods.
I was told by the dealer that I cant run a roller secondary becaus my sled has RER, Is this true? If so, why??
I also have a problem with failure to shift up past 7500 rpm when the clutches get hot. Ive tried running the 800HO belt, the Dayco Ultimax3 and factory 600HO belt. Tonight I removed the plastic from the belt guard, hopefully that will get more airflow throught the clutches. Any other tips?

Springtime riding in Alaska is just opening up, and I really dont want to be down with problems... Any help is appreciated
Rolling