biped problems

Right I am in the process of adding bipeds to models that do not have any skeletal structure. Now I have tried to envelope 4 models now and i always seem to get the same problem. The fingers always seems to leave a vetex behind that I can never seem to envelope no matter how big i make it. Also i noticed that when rotating the fingers, the biped finger always comes out the mesh and the mesh finger seems to stretch/deform. How can i fix this

 

You can select vertices with Physique and link them to a specific biped object.

As far as the biped parts going through the mesh, you need to make sure that the joints of the biped are in the same place as the joints on the mesh or they aren't going to animate correctly which will cause the weird distortions.