This is certainly a solution for what you’re describing. You can certainly run multiple libraries simultaneously (even on the same server: you just need to set up each library to use different ports).
I think this would be a lot easier once sharing is built out.
Stepping back a bit: why do you run a VPS? Is it a workaround for limited upstream bandwidth from your home? I’ve found that browsing a large PhotoStructure library over a 10mbs link is actually fairly reasonable (especially image-heavy libraries). If necessary, you can also set up transcoded videos to have a max resolution, frame rate, and bandwidth to make streaming reasonable over constrained upstream links.