I have finished of fixing the skeleton and bind it again, starting again the process of painting the weights. I found some problems when I used symmetry with the weights because some bones weren’t bound so I had to bind them to the mesh and do again the process of symmetry. I had also to repositioning some joints like the shoulder, clavicle and ankle.
I look for a tutorial in order to use IKspline for drive the back, the tail and the tongue of the characters. I found this interesting video: