why would one secret sharer not know who the other secret sharers are? is there a reason to keep then in the dark about each others identities? if the identities were secret then what stops dooglus from being all the identities or not sharing the secret in the first place? if all identities were know, PGP signatures prevents hoaxes, right?
I'm not at all clear what it is you think secret-sharers would be signing/decoding. There's no function that I'm aware of in Bitcoin for a wallet to have n of m signing (transactions can - but that's not relevant). So what is it you think they control? The whole process becomes very unwieldy rapidly with new secrets having to be generated after EVERY movement of funds (because there's no way to apply an ongoing n of m signature requirement to a wallet).
And there's practical difficulties unrealted to technical aspects :
Who are the trustees? If you looked back a year or so and picked the most trusted individuals you'd fund a lot have now scammed/defaulted.
How do they determine a withdrawal request from dooglus is legitimate? Do they have contact details for all account holders? Do they have to publish a request for anyone else claiming the amount and wait a few days before allowing large withdrawals (in case it's a dooglus sock-puppet pretending to own someone else's large deposit)? After how much of the BR has been paid out do they stop authorising withdrawals without a full audit?
If the house takes large losses does J-D have to close down for a while whilst the trustees collectively check it isn't dooglus manipulating results to syphon off cash?
The moment you appoint people specifically to prevent him stealing they MUST then always assume he's acting in bad faith until proof of good faith is provided - or they become toothless watchdogs and he can still steal most of the funds by jumping through a few hoops making the whole exercise pointless other than for PR.
Who pays for their time and effort - it in no way benefits dooglus (if he intends to steal obviously it doesn't, if he doesn't intend to steal then he's accepting a non-zero risk for no benefit).
In theory dooglus COULD act to satisfy your concerns without risk to him. Way to do it would be simply to allow maximum risk to be up to 100%. Then you could all micro-manage your exposure via API or via some third-party you decided to trust.
So if you accepted that with trustees dooglus should only have immediate access to 10% of funds you could approximate that by only depositing 10% of your own funds with a 10% risk on them - you'd then be risking and gaining the same as if he held all your funds at 1% (assuming all bets were spread evenly across all risked capital).
And if you didn't want to micro-manage it yourself you could indulge your own personal level of paranoia to any extent you chose right through to:
Forming an investment group with other like-minded individuals
Hiring a lawyer who employed staff on your behalf to manage the funds
Instructing them only to send topups if N of M of your group provided crytographic proof along with a photo of them holding the current day's newspaper plus their passport and with a shoe on their head.
Then he could only steal 10% of your money. But no doubt the complaints would still continue that he could steal other people's and that those not bothering with these precautions were making more profit. And there's the root of it - I believe the current risk (and the reduction of risk if a solution was put in place) doesn't justify the cost (and the new risk). You and some others apparently do. So come up with a proposal where you bear the cost and get the benefits you believe exist (and the risks I believe exist) and we have something to discuss.
An alternative to the above would be for dooglus to allow accounts that had a notional balance higher than their actual balance - with the account-holder having to top up before they got more action if their actual sent funds were exhausted. In practice that works very much like allowing increased risk - it just accounts for it differently. It does fulfil the same (to me) major objective - that the effort and cost of maintaining partial exposure is placed firmly on those demanding it.