Multisite vs Multiple install: advise on site structure

I am working on a startup platform for a niche audience of Designers, Photographers and Writers. There are five aspects to the site, 4 of which will be run on Wordpress/Buddypress with plugins. The fourth is built from scratch.

The four WP aspects are:
1.) Academy - provides content (free and paid) such as lessons, royalty free art, etc. Includes Q and A section, Wiki Section, Premium Memberships and blog-like content posts.

2.) Social - Buddypress with some plugins to help artists find other artists interested in collaboration

3.) About Us - Yeah, all the privacy policy and about us jazz.

4.) A multisite that allows organizations to set up their own limited wordpress site and curate content

All sites have the same theme, and will be seamlessly integrated to the end user. Each user will have one user account, and we are creating a widgetized personal dashboard for a single notification point. We are disabling the wp-admin for all subscriber-level users.

About Us will (obviously) only be accessible to admins.

My question: would you recommend multiple installs or multisite? The url structure will be
site.com/academy
site.com/social
site.com/about
site.com/org_one
site.com/org_two (and so on)

So, all the academy stuff will be under academy (site.com/academy/q-and-a/).

Any suggestions?

Thank you!