Your bike would be fine for the slickrock trail. I’ve seen some 29ers on Porcupine rim before. They were hardtails. i wouldn’t want to punish myself like that. That trail is rough. I don’t care what anybody says. there are sections that you have to go through where there really isn’t a smooth line. Just smoother than the roughest. If you do Porky, rent a FS bike.
The hardtail should be fine for the rest of your riding. I’ve ridden in Fruita before, and i remember it being relatively smooth.
Don’t get me wrong. I’m not saying you can’t ride Porky on a hardtail. It’ll just punish you. Your knees and ankles will be worked.