MulitSite for Shopping Mall site with minisites for stores

This question might be a little more entailed than usual.

I have been provided an html / css template from a client for a Shopping Mall website. They want it set up so a super admin can set up new stores. The stores each get their own login and minisite that all look the same but with some customizable fields that each store can customize. The header and footer will remain the same as the main mall website.

I was thinking of utilizing the multisite feature for this. The primary website will be the mall and each other site will be the stores websites. I have a couple of questions regarding this approach.

  1. The stores will be organized in different categories on the main site. How should I (or would you) set this up? Is there a way to categorize each of the minisites?
  2. There is a dropdown list on the main page with all the stores. How can I populate this dynamically?
  3. Should I utilize child themes based of the main theme for the store websites or would you simply create 2 separate themes? I’m thinking child theme so the header and footer only need to be updated once if they desire.

I’m sure I’ll have more questions but this is all I can think of for now.

Any information would be greatly appreciated!