On the subject of Mousse challenging Shampoo...

Ehn.  The law is phrased so as to apply to outsiders.  Mousse's 
behavior in the main line indicates strongly that he doesn't qualify
for that route to marrying Shampoo.  

I have a suggestion.  Perhaps when this Mousse went away he was 
exploiting some other rule about how a male can become an outsider which 
requires exile for six years.  

Now he hopes to force Shampoo into marriage