I want you to know that I started with my clipless on a mountain bike. When you forget to unclip in a bad trail, well, trees and rocks are unforgiving. If I didn't come out of the trail with branches in my helmet, and at least a raw elbow or knee, it wasn't a normal day. You mentioned practicing your figure eights. I actually went through a police mountain bike course ( I get to ride a bike at work) and cone courses were a large part if it. For better control of the bike on slow spots so you don't tip over, use the rear brake as a resistence. Keep pedaling but with the brake slightly on you can maneuver better in tight spots. Don't try to much at once until you get more comfy, I think you are expecting a lot out of yourself. Try the water bottle thing in an open area and look if you have to. There's nothing worse than dropping it and then running over it. Done that a FEW times. Hang in there, you are doing great.