Is it OK to ask about a choice of a crowdfunding site (specifically, about which of the popular sites meet certain criteria) for my open source project?
Questions about off-site resources and recommendations (in this case, a crowdfunding site) are explicitly off topic. In fact, there's even a specific option in the "close" dialog for such questions:
Questions that ask for off-site resources, or for a recommendation of an open source service or product are off-topic because they don't directly concern an issue related to open source development. See: What's wrong with external resources questions? for more information.