i would do it if i were you...
nah, unless you wanted to do full suspension and shit like that...otherwise, geta roller and a motor and you are good to go..i guess that depends on how much you spend on the roller...
just use the 450 radiator...itd be a simple hook up..pluis youd have the fan..
you can cut and weld anything...i think itd be fairly simple..
might see if the elkas will fit the 450 frame. i know the 450 shocks will fit a banshee with little modification so i dont know why you couldnt use banshee shocks on a 450...