I put it on my 2010 and it is probably the best money you will put into it. It definitely feels tippy on your first ride out but you get used to it fast. After a while you will wonder how you ever rode it with the wider stance.
Technically you can, but I have been told it changes the geometry so it will not handle and work as well. Having said that, I kept my Evol Rs on for a year after putting the S36 on and cant say I really noticed anything negative? I sent them out last fall and got them shortened to the proper length now. Its hard to say though. I think you would have to ride two sleds side by side....one with proper length shocks, one with too long of shocks.....and then make a comparison. It can be done though.