Django - multi site
Better idea to use sites framework? 

Yes.

I don't think so but I could be wrong?

No. 

How would django handle many websites?

vhosts.

Could it be solved through some kind of middleware?

As well. Sure.

How to go about that?

Pay a programmer
I am currently planning to build a SaaS e-commerce application in python (django).
The application will create new e-commerce websites as requested. Each e-commerce needs its own templates/configuration but the core functions stay the same. Each owner decides what goes where and the page layout.
So, from what I understood, I would have to create apps separately from the projects so that they can be reused across all the sites but each website has its own project with a different config. since each website has its own database.
My questions are the following:
Would it be a better idea to use the sites framework given by django in this case? I don't think so but I could be wrong?
How would django handle many websites? The web port can only be used once so spawning more than one django server is not a possibility. Could it be solved through some kind of middleware? And in which case, how would I go about that?
I am really interested to learn and would really appreciate all the help I can receive!
Thank you very much for your time. :-)