I don't know if this can be of any help, but I'd like to offer my experience of this situation.

I have 'worked' on projects similar to PerlMonks (in that there is a community, there are moderator, janitor and god equivalent positions). These 'higher ranking' positions are by invite only, and mostly thankless - carried out by volunteers.

How absenteeism is handled: Upon invitation it is explained that holding the position means that person must be 'active'. Any up-coming period of in-activity (for whatever reasons) should be brought to the attention of the 'gods'.

How other 'administration of the admin' compares to PerlMonks: firstly is that there is a little more apparent (now I base this mainly on this thread) open-ness as regards to how things work and how they are implemented (within the 'higher rankings'). And secondly open discussions (such as this thread) are discouraged - enforcing the understanding that as thankless as the position is, it is a privilege not a right.

I admire your efforts here. Keep up the good work.