I think you should try for a 100% reserve scheme where the holding addresses are publicly known. Only switch to a different scheme if you can't find enough people willing to help run a 100% reserve system. Using a 2-of-3 or similar key splitting scheme is a good idea too.
This. I see no reason for it to be done any other way. While I am sure there are trusted members in the community, the spirit of Bitcoin is to remove third party trust.
Using an n of m setup and a verifiable holding address provides transparent accountability. Really there is no reason not to do that. I think even a 5 of 7 key structure would be workable if the funds are being used more like a savings account than a checking account with small amount held by forum admin for day to day operations.
I approve this post. No reason not to keep 100% funds available into a public address. Multi factor is also a necessity, we don't need another Bitcoin fiasco that would keep donators away.