Great topic, thanks! Of course it's in my best interest to get more people involved here and less on Facebook.... 
Currently, we have a single moderator, Tom Moloughney, who has been doing an amazing job of keeping the forum clean!
File and Image Uploading
Correct - no images and files can be posted. This has been this way since the start of the forum in 2013. It was to limit the amount of moderating needed - spam comments with crude words are a lot less shocking and invasive than an image!
Images can be included from third party sites, but there is the risk of those sites deleting the file or not allowing it to be hotlinked.
Yes, there is a payment option that allows you to upload photos and files directly to the forum. On the main forum page (http://www.mybmwi3.com/forum) when logged in you'll see a message below the banner.
Privacy
We don't do anything here other than ask for an email address to verify account registration. Yes, we do have google ads on the site and I guess those track you somewhat, but we personally don't do anything.
Oh, we also have a single-sign-on which tracks your email address from one EV forum to another to allow you to login with a single click if you are registered on another one of our forums.
Income from the site
Currently, income is from the banner ad at the top of the page and at the bottom of the page - it isn't enough to open up file uploading to every account and still provide a fast/reliable server. We also make a small amount from the forum memberships.
Future Plans
It would be great to be able to make enough off of the simple banner ads that we could cancel out the paid-membership upgrades, but I don't want to have more 'visual' spam show up because of that.
I also don't want to pollute the forum with banner ads everywhere to increase income to cover costs for image and file hosting, so I'm not sure what to do about that.
I have thought about making a more general EV classifieds site (instead of classifieds on each specific forum) that would be a way to generate some revenue while providing a worthwhile service?
Feedback is great - keep it coming!