Hurd-L4 : Architecture Questions

[NePat]

                Hello,
  I've spend much time in reading documentation on L4-Hurd, i read some code , 
i also read some mails in the mailing list, and i have some questions to ask 
(excuse my poor english :) ) :

1 - Trusted process ?
        There's lots of things and thought about, but i don't really get the 
thing. 
        On what is based the amount of trust provide to a process by a server ? 
Why 
        it can't be enough to trust the owner (user) of a process ?
2 - SMP are'nt thinked ?
        I don't find anything about SMP ans L4-Hurd. Altought the L4 pistachio 
seems
        to be designed in such a way. And , the heavily muti-threaded conception
        of Hurd-L4 is directly interested in SMP. And more, the futur, by the 
limit
        on electronics size, is to the SMP. So ...

It seems that the design changes his way to a more centralized system ( with 
cap server and notification server, perhaps there's the same ), but in SMP 
architecture centralisation is a bad thing ( i think ), the things has to be 
as much as possible local, so are the reason to change the way so 
unbreakable ? ( and i don't speak about overhead costs ).

Thanks,