UPDATE: DDUBS First Custom (WIP)

Well, just some friendly tips, slow down some and wait for one coat of paint to dry before going again. Thin your paint down with a dab of water as well. I'll tell you from experience that white is a hard color to get perfect coverage with. It takes me forever to do that much stuff white. You might try your hand with getting a few layers of paint on there and then using some white spray paint. The reason I suggest putting some paint on there before spray paint is because I haven't found a spray that doesn't take forever to dry or doesn't make the figure "tacky."

I'm also assuming you meant the joints are the where the paint has "scrunched up." I never tear apart the leg at the thigh cut but one thing to try is remember use very little paint on your brush and actually spin that joint some when painting to make sure that you dog any kind of wrinkles if you ever do try to move it. I do take apart the calf and thigh from the knee joint. So you should have the thighs, the knee piece and the calf piece. Now literally use some sandpaper or a sanding sponge (I like 3m fine sanding sponges because you can wash them off and use them for a long time.) and sand the nubs of the thigh the nubs on top of the calf, and sand the entire knee piece. The more you sand them the less paint rub you will have when you put it back together. If you don't sand enough, the paint rub or "scrunching" as you put it will happen again.

As for clear coat, what did you use? Depending on finish, I use Krylon of some sort. It's really flat and probably the closest thing I've found to a factory finish flat.

I think this stuff is what I used but I can't recall, I will need to go back and to the store and look around because I used it all up and forgot what the can looked like. www.krylon.com/products/matte-finish/