> And second; why I can't use su-command even though I thought I switch=
ed =

> my group to wheel?

That would probably be because ... well, the correct way to enable
"su" access is not to switch the primary group to wheel, but to add
wheel as an additional group for that user by adding the user name to
the wheel group entry in /etc/group.

As shown in the manual page su(8):

     Only users in group ``wheel'' (normally gid 0), as listed in /etc/=
group,
     can su to ``root'', unless group wheel does not exist or has no me=
mbers.

Regards,

- H=E5vard