I would say the majority of posts on Reddit are admin ran karma bots and scammers. Just a bunch of bots talking to themselves.

Its hard to say and I really wonder about this. Specifically, I think there is a lot of astro turfing, but not in the way most people think it is. I think very specific subreddits like r/marvel, formula one, celebrity news (which only really started making it to the front page in earnest 2 months ago), are some how in cahoots with reddit to sponsor their popularity. The game goes like this: you work with reddit to astroturf organic engagement with the channel, and over time, organic engagement takes over.

I think this is how Reddit makes real money and I wonder if they give two wiffs of piss about the embedded ads. I think you can attribute the success the modern marvel franchises have seen as well as the success that the modern star wars series saw to astroturfed social media campaigns on reddit.

Its pure conspiracy, I have no evidence other than watching the way that reddit has evolved.