@ben, I think this is a good start. What I'm missing is provision of how the funds spend on the grant are tracked and reported back to the shareholders. This can be under 5 or 6, would prefer under 5 given the importance I would assign to it.
e.g. way of publication of list of transactions, receipts, real-time, once a month, on request, on website etc., conversions to other crypto/fiat etc. Imagine that some proposals would require almost nothing of that (e.g. can be found in blockchain) where others would need a decent administration and scrutiny to ensure everything is done properly.
Given that apparently shareholders may vote for different amounts than the requested amount, I also suggest the proposal includes a bandwidth on when a certain vote would be considered a yes during counting. Example: Voting yes for $1 for a grant of 100k is practically a no as it will be unlikely that any outcome can be achieved. Clarity upfront will help with voting and counting the votes, instead of uncertainty afterwards whether a grant should be provided.
I understand that this might complicate the voting process, I would rather see a protocol change where you can't vote for different amounts, for or against vote, no greys.
Just my views, open for comments and looking forward to your proposal Ben.