To Chris Wood - Great to know that you're keen to get involved and I agree with others that we should try to be as inclusive as possible.
With only two days to go until close of nominations, I think it's too late to change this rule - that has already been agreed by consensus - that only 18+s can be candidates for the initial board.
However, one of the first things the new Board will do is draft the rules of the chapter - its Memorandum and Article of Association - which i guess will include details of the voting system for members of the subsequent Boards - so please do input there. I personally hope we can come up with a situation which allows 16-18s to be members of the Board but also satisfies the Charities Commission. As you already mentioned, the legal restriction is that Limited Company Directors have to be 16+ but the Charities Commission also has the power to intervene if they fear "mismanagement" of the charity. I've put more details up at http://meta.wikimedia.org/wiki/Wikimedia_UK_v2.0/Candidate_FAQs#Why_do_Board...
There is nothing to prevent you from putting your name up on the list, but the election committee will probably decide to invalidate your candidacy.
While we're on that subject I presume that everyone is happy for - geni, Andrew Whitworth and Jo Seddon - to be the election committee. In that case, I'll put details up on the wiki. Also, is it the consensus that we drop the 50% rule?
As to guarantor members, I am not aware of any legal restriction on the age of members. I can't think of any reason we would want to restrict it to over 18s, but I guess this is a decision for the inital Board in consultation with the community.
Alison made an interesting point about it being a good idea if all intial Board members had lived in the same place for three years, weren't private renters, had bills in their own name, were in full time employement, had no CCJs and were UK passport holders. I wouldn't want any of these to be a requirement for someone to be a Board member and I don't think it would be fair to introduce this at this stage, but I've added it as a "voluntary question" here: http://meta.wikimedia.org/wiki/Wikimedia_UK_v2.0/Candidate_questions as it might be useful for voters.
Finally, someone mentioned it wouldnt' be a problem if a person who was a potential risk to children got hold of a U16's address because it would be their parent's address. My though was, they may also be able to get their phone number, email address, IRC contact, facebook/myspace page etc etc - you'd be surprised how much information is readily available. That's the issue I think we should be careful of.
Andrew Turvey