sagging edges and weightmap

I am creating a skirt and all is going well except a couple issues.
First is visible in the attachement below. The very bottom edge of the skirt is straight within blender but shows a visible sag within makehuman. i have used the skirt helper for the vertex association but that does nothing for the sag. this sag is also effecting my texture, giving it noticeable stretches where i don't want them. is there a way to limit this effect? did i miss a step? i realize stretching is not avoidable, but i cant see why it would sag.
second issue is when animating the rig. the legs are visibly passing through the skirt mesh. how can this be fixed. do i need to weightmap the skirt? I want to be able to use this mesh on any character without passing each character(rig) through blender to weight map them. So i am hoping the mesh preserves weight mapping (if that is the cure).
Thanks
First is visible in the attachement below. The very bottom edge of the skirt is straight within blender but shows a visible sag within makehuman. i have used the skirt helper for the vertex association but that does nothing for the sag. this sag is also effecting my texture, giving it noticeable stretches where i don't want them. is there a way to limit this effect? did i miss a step? i realize stretching is not avoidable, but i cant see why it would sag.
second issue is when animating the rig. the legs are visibly passing through the skirt mesh. how can this be fixed. do i need to weightmap the skirt? I want to be able to use this mesh on any character without passing each character(rig) through blender to weight map them. So i am hoping the mesh preserves weight mapping (if that is the cure).
Thanks