I saw that vid a few days ago. I give the guy a lot of credit. We ALL make mistakes and he shared both his mistake of forgetting to put his side panel back on AND his mistake putting the pulley on backwards. Making a mistake does not make one a "noob" or a "dumbfuck" IMO. It make you human. IMO, forgetting the side panel should NOT cause the pulley to fail like that but that is the price one pays for cutting weight not unlike the bent tunnel thread. Anyways, Kudos to him for sharing his mishaps. We ALL break stuff (if we ride at all) but not everybody is willing to share their mistakes. The lesson here is, if you hit something and smash your side panel and are running QD2, even though your machine is still mobil under it's own power, better tow it out anyways lest you get some snow on the drive.
No.
How heavy do you build the pulley? Is it Polaris fault if you stick a tree branch in the pulley? Snow is water, water doesn't compress. Stuff it in there full enough and the belt or the pulley is going to blow.
Everything has a fuse. Build it to never break and you'll have a tank. Build it to be light and fun and you're going to break stuff when you get stupid.