Strange modelling problems

The arm is set as vertex group. Move the vertex I selected with g key and you will realize it is not connected to arm I used extrude snap to edge to make it. There is also problems with the legs in some 4 vertices
areas I can’t make faces.

Attachments

untitled.blend (296 KB)

What is the solution

Not sure really what you are asking but note that faces cannot have more than 4 vertices, an added edge loop and remove doubles connects the vertices in your original mesh (attached blend file)

Attachments

untitled (1).blend (298 KB)