Pretty much anything goes, but try to keep your activities semi-productive. Build cool stuff rather than raid everyone. Raiding/griefing is technically allowed, but if a player or faction is caught doing so excessively, they will be warned and/or banned.
Age group is 18+ in an effort to keep the community more mature.
AMD FX-6100 6-core
16gb RAM (8gb currently allocated to Tekkit)
1gbps ethernet connection
Only running one Tekkit server, so performance should be great.