Multi-DB and Multiple Servers?

Hi,

Of course I understand the benefits of the Multi-DB plugin, however I'm not sure if it takes care of all the scaling we would need in the event that we grew immensely.

Of course, the goal at that point would be to split the network over multiple physical servers. My questions:

1) Multi-DB does make it easy to do that, right? I believe that I can specify a datacenter, IP for each database, etc., right?

2) Does it matter if those databases are in cPanel installations on other servers?

3) Even if I'm distributing my databases across multiple servers, are the files for each blog still being put on the original server (in the blogs.dir directory)? If so, then I think we still have a problem...if, for example, there are tens of thousands of blogs and all of their images (and such) are still being put on the original server. We're still going to fill up that server and have most of the traffic there (with some of the load deflected by users who have CDN). Or does Multi-DB also distribute the files somehow?

4) If Multi-DB does not distribute the files themselves, what is the best option for scalability in this regard? Edublogs might be the perfect example case...if you don't mind revealing more than you already have, how do you handle this scalability item?

Thanks and best regards,

Mark