su and mysqld

hi

two things

I know that the user must be part of "wheel" to be able to root, but none=
 of=20
my users can su even to one another ... ?  Whats up with that ?

The other thing.  My mysqld doesn't start up properly.  Well.  It starts =
but I=20
can't connect to it with mysql command.  I het a error, "unable to connec=
t=20
through socket ..... " I check and the socket exists ... So if I try to s=
top=20
te mysqld service I get an erro "[!!]"

how can I fix this ?

regards
pieter