1. Problem is not with waist but with Thumb. I do not recognize figure which you use, but most poser figures has "Thumb1" there. Add it to collide against list.

2. Belt usually is checked as a soft decorated group. Anyway I think in this case should be constrained. You should add to constrained group kimono under belt as well. Easier to do in wireframe mode.

Belt should not be 2 sided or (if you use belt similar to torus) normals should have the same direction inside and outside - in pose window open grouping tool, chose polygons inside belt and "reverse group normals"

3. Tunic on breast look too loose. Maybe you can try scale figure 90 => 100% in first frames.

4. Skirt looks very low poly.

5. Tie is part of cloth which cen destroy simulation. I have no idea what kind of group can be used as a tie. Scarf can behave weird colliding against it. I'm not sure, but scarf looks like 2 sided mesh. It is hard to simulate.