1. rm -f /home/usr/ *mp3.*
2. cat /etc/services | more
3. хм... слишком обширно
ну скажем 80 - apache, 22 -sshd, 20-21 ftpd, 25 - sendmail/postfix и т.д.
4. полностью - 105673. установлены биты:
- set UID on execution
- sticky bit
- read by owner
- write by owner
- read by group
- write by group
- execute/siarsh by group
- write by others
- read by others
5. хз...