[1] Have not been member of forum long enough
[2] Don't know if comfortable holding over 100 btc, while I have very secure robust methods, the price has gone up, and I would rather see more holders of smaller amounts say 100, as this would make it more distributed and less than one point of failure. Competing with that is finding enough trust worthy people.
[3] I would have thought full reserve would be required as it would be hard to re-insure against an evaluation eg the recent run up to 600, it would be much more sercure to allow a fixed storage and handling charge
[4] I think an even mix of known and anon trustees would be the best way to ensure distributed and no single point of failure.
[5] I can however look at the contract(s) and maybe make some commentary.
[6] Have a mix of single sig and multi sig accounts. Probably no more than 2 sigs per account as people disappearing or un-contactable could lock up vast amounts of btc
In relation to [5] some comments for example on the "agreement"
I'm not sure an agreement can have any force where it is non-legal, I think you know this, but what you may mean to say is
also where ever the server resides the courts would probably declare that their jurisdiction is in force. (courts don't like privative clauses and love to enlarge their jurisdiction) but what courts will almost always enforce is where the parties have agreed to alternate dispute resolution first, and would not allow the matter to go to court until that process is exhausted your disputes part probably serves this well but I have not had time to analyze this yet. Further there could be a form of estoppel that arises if you draft it right to stop parties going to court. Alternatively you could define a jurisdiction that prevails. Sometimes where the agreement is made determines jurisdiction, that may be the place where the receiving address resides.
further to say
"agreement is intended to be enforced in a ... non-legal way by the community." could be read you intend to enforce it in an illegal (unlawful) way
a better wording would be
you could then go on to outline a specific process of alternative dispute resolution
so all together perhaps the wording would be
this gets a bit tautological, and its not perfect but it's all I have time for right now