A couple of things, one is that fixing Miki's mesh problems won't have any bearing on whether clothes fit or not. The issue would be morphs would not transfer. On the other hand, fixing the mesh and making it a single mesh makes it possible to make joint correction morphs to fix the poser rigging problems. Part of Miki's rigging problems are due to less than optimal rigging, but much is due to the way Poser does rigging.