Group Funding

One major problem is enforceability.

Many of these people could be earning 10x their living expenses

This premise seems questionable, though it's vague enough ("many" in relative or absolute terms? are we looking at wannabe researchers in some specific field or in general?) that it could be correct.

In general, I would expect that the amount of people capable of earning 10x their living expenses are quite rare, especially since a person tends to spend more money on their living expenses when they start earning more.

Depending on the field, research costs A LOT more than living expenses.

This is also overly complicated. There are many people who ALREADY earn significantly more than they need. It seems far simpler to convince them to fund researchers than it would be assemble groups of 10 researchers and hope one manages to strike it rich.

Finally, of the people who would like to do research, how many are actually useful? I imagine a lot more people want to do research than are actually good at it or working in fields where new research is crucial.

At least for the single, communal living with people on a shared project seems more likely to work. As someone else pointed out, enforceability, and trust, are obvious issues in your plan for "You support me in my research, and then when I'm making boatloads of money, I'll do the same for you."

This is vague enough that it might plausibly induce equally abstract solutions to the same problem, as it doesn't have many details to criticize. That would be good.

More likely, it won't begin a dialogue at any level of abstraction other than those below it. This is the problem with proposing solutions as a conversation starter.