My understanding is thus:
Reddit is like a massive forum, and each sub reddit is like a sub forum under it. So the content of the F&C section would be a good example of a subreddit. However in a forum, the newest post is at the top, whilst on a sub, the most voted post is at the top. Posts can be voted up (we think it's good) or voted down (we think it's bad). Content literally becomes a popularity contest.
Responses to posts are nested within the post and you can reply to individual replies, which sparks more conversations. It's a bit like the quoting system but it can kinda derail the conversation. Not worse, just different to forums. One of my favourite subs is
/r/dadjokes as an example.
Images are pretty badly catered for in Reddit. You can't embed them into the post (only the OP). Something like "Show us your film shots" would be just a list of links out to Flickr or Imjur or some other image hosting platform. Can't even embed the images from Flickr like you can here.
In short, it would work, it would be free, but it wouldn't have the same functionality. And if you wanted to have separate "areas" to discuss things you would need a separate subreddit for it.