You don't necessarily need to have a lot of edits to be considered to join the staff, but as long as they are of good quality (it's quality that's important, not quantity). Keeping yourself out of trouble is certainly a help as the last thing we want is to turn someone into an admin only to cause havoc around here.
4. can be counted on to ensure the integrity of the site
5. not be intimidated by those who come in to troll the site
If there is a need to add more administrators to this site, there may be a nominating process, and then a vote amongst the active members of the site to determine who becomes an admin. At that point, it is up to the bureaucrat of the site (AngryHearts) to decide if the people selected are good enough to become admins. In some, extremely rare cases, AH may decide to select someone who has been making positive contributions to the site to become an admin, but that's her choice.