useradd, groupadd, passwd, lpadmin (or lpset), vi
serial port configuration is harder.
pmadm, sacadm, and syncinit appear to perform the job, but i have to say that i've only ever configured serial ports with admintool ... it takes a lot less time, and i only need to do it once on specific machines
btw 'vi' _is_ sensible, if you know the format

vi /etc/hosts
vi /etc/group 'GA<return><groupname>::<gid>:<esc>:wq<ret>'
vi /etc/passwd 'GA<return><username>:x:<uid>:<gid>:<comment>:/home/<username>:/bin/csh<esc>:wq<ret>'
vi /etc/shadow 'GA<return><username><esc>8A:<esc>:w!<ret>:q<ret>' then 'passwd <username>' ...
vi /etc/auto_home (which by the way admintool doesn't seem to do) 'GA<username> <server-of-home-dir>:/<path-to-home-dir><esc>:wq<ret>'
Jon