I prefer your third option:
- Free-for-all, with each question pulling its own luck depending which voters to open/close are in which camp?
which I think equates with a more impartial wording of:
- Allow such questions to be voted on (including vote to close) as they present themselves to each user eligible to vote i.e. a case-by-case basis
I think that a strength of the Stack Exchange model is that it allows users who have committed to the model, by achieving different reputation levels, to cast votes (up, down, comment, close and delete).
I think another strength of the Stack Exchange model is that it uses a minimum of enforced policy that enables it to allow communities to evolve rather than be locked to policies that sometimes become outdated.
By all means try to provide scope guidelines using per-site Metas, but I think changing the scope of a site more formally, as defined in the content of the
/tour pages, should only be done when community consensus is much clearer than the opinion split that you describe.
As an example, on a site I moderate and am an active user of, I make no secret that I think questions asking for recommendations should be explicitly off-topic (like they are on many SE sites) and I would like the community to endorse me changing the
/help/on-topic page to say that - see
Should questions asking for product, service, data and learning (course, book, website) recommendations be closed?
However, community consensus is not behind me to do it so all I can do is to keep editing my question to try and make my case clearer, and in the meantime exercise my downvote when I think any question is not useful, and my close vote on any question when I assess it to be off-topic according to the
/tour pages, and any Meta Q&As where consensus is clear.
Unfortunately, I feel my hands are tied on closing any recommendation question for the reason that it is asking for a recommendation, but it is the community's current consensus that we should not do so. This is my personal "policy", and not an SE or site policy (nor do I think it should become one).