Alright i change my vote to 3, heres my input on the reasoning, if our choice ends up being three (otherwise my contribution will be useless as i'll be asleep for the final hours due to upcoming exams)
Why 3 is better than:
1- Even though 1 has been here longer, three years is a sufficient amount of time to know all the rules and understand the way a ck should act, whether 1 has been here two more years that 3 or four more years really shouldnt make a difference. Avoiding the general forums means 3 probably doesnt have as strong a social connection with the community but as mentioned he is 'well respected' and we know people already listen to 3's advice. A veteran would send out a more authoritative dominant role which would seem to be intimidating to new members.
2- 2 hasnt been here all that long and as such we know 3 has a lot more experience for one, and of course its evident 3 is more mature. theres not much to say on this matter, 3's superiorities to 2 are quite obvious so i wont go on.
4- Someone who has Run-ins with staff doesnt seem to be a good idea for the type of person to be working with them. 4 seems like the person who would abuse thier power just a few too many times for the sake of humour and the role of ck should be taken serious at most times. There is also nothing in 4's description to imply he is helpful to the community beyond providing spam like entertainment, unlike 3 who as mentioned, is helpful.
5- The main point 3 has over 5 is the activity level. 5's bursts of low activity and high activity dont seem to be all too apealing, an inactive ck would be ineffective and lose pace with the happenings of the forum and the community. This person in my opinion is more deserving of a "recognised member" title rather than a ck title. As mentioned 5 avoids confrontation and it would be harder to figure out a way to confront someone when you only get to know the community in bursts.