By default a would-be vendor cannot be fully registered without creating a listing and having that listing be approved by the site admin.
But once the vendor is approved (via listing approval) that vendor should be able to publish listings without the listings pending admin approval.
Preferably I would like to have it so that verified vendors can publish listings without admin approval, whereas registered, but not verified, vendors can only submit listings for review/approval.
Unfortunately, there’s no such feature, it would require a custom implementation. In this version, you can only use the manual listing approval feature.