What are the advantages and disadvantages about having an initial moderator selection and then never renew them (as long as they don't themselves step down) and having periodic elections where all moderators would have to seek reelection?
This is very much dependent on the type of community. Some communities are hierarchical where you work you way up earning reputation and respect through quality posting and actions that help the community. In these types of communities the length of time you've been with the community is important, as is how much you've contributed towards the community. Being made a moderator is often a sign of honour and trust and is quite often for life.
At the opposite end of the scale you have communities like Stack Exchange where how long you've been involved in something doesn't matter at all, just how well you can do the job. There's a minimum limit set before you can put your name forward to make sure you can do the job but other than that anyone can put their name forward to be a moderator and it's then down to the rest of the community to vote between them and choose moderators for a set period of time.
The point of doing this in actual democracy (i.e. countries), is to give the leaders the motivation to actually get stuff done for the people (otherwise, he won't get re-elected).
In a community, a moderator is viewed and valued every day. If there's a problem with his performance, the community would instantly notice and (hopefully, if you put the system up for it) raise flags and discussions about it.
For that reason, I feel that electing moderators for a certain period of time is pointless. If the moderator is not performing well or is abusive ('corrupt'), his moderation status can be instantly terminated, without having to wait 4 years for the next election.
I'd personally say yes. Why? That's how the US Supreme court handles it, that's why :). They have some of the same worries of too much power and judges afraid of not getting "reelected."
The founders believed that an independent judiciary was critical to the success of democracy. To that end, they directed that federal judges be appointed for life; they can be removed from office only if impeached and convicted by Congress of "Treason, Bribery, or other high Crimes and Misdemeanors."
- If a mod is bad they can't be impeached
- It'd be easy for mods to get replaced with ones without experience
- They can make tough choices without fearing to not get reelected
- Elections can be stressful for some people, so this may make a mod not run for reelection
I'd personally go with the strategy of lifelong election but with a formal process so they can get impeached if needed. They should also be able to easily step down if they can't contribute any more.