[OS X TeX] Installing new fonts with MacTeX 2011

[Alain Matthes]

Hello

I  would like to avoid recurrent problems with TeX Live Utility when I update a lot of things.
Often I have an error because some .map files are not found.

So the question is simple. I work on "my" mac, I'm the administrator and the user and I can destroy it
 if I want :)

I have some commercial fonts,  some "casseaux" fonts ( thanks to JY Andre) . Sometimes I put the fonts
 in my personal texmf folder , sometimes in the texmf-local folder.

There is also a texlive folder in my library, useful I think for texdoc and other things.

Sometimes I need to use --syncwithtrees but I don't understand what I make when I use this option.
Sometimes I need to remove .texlive but actually I don't see this file in my home.

Well , I would like some explanations about all of this and what is the fine way  for an ecstatic experience
 with MacTeX 2011 and TeX Live Utility.

Thanks to all the people who work on all these useful tools

Best regards

Alain Matthes

PS : I always find a solution to make what I want but if you can give me the simplest way,
 I will be very happy.