Cross-base data sharing can be done, but it requires either a third-party integration tool like Zapier or Integromat, custom API code, or some combination of both. You might consider posting in the Work Offered category if you would like to get assistance with building such a system.
As for the availability of table/view folders, only the devs know for sure, and they’re pretty tight-lipped on what requested features are/aren’t in development.
On the subject of custom access privileges, you might look into Airportal. It’s still in development, but looks like a promising solution for customizing user access.
