Wow another wonderful article full of gold! Thank you.
Now one question. After reading your previous article on how the rshare claims work and now seeing how much STEEM is added to the pool, what determines how much of the total available STEEM Pool is actually delivered as rewards per day? Clearly the entire Pool is not emptied on a daily basis so there must be some limit attached to this which allows the pool to be drained without being emptied entirely.
Good question. In short: The reward pool itself.
The reward pool is used to calculate the value (number of rshares) that is added to a post when the post receives an upvote. The lower the reward pool, the lower the number of rshares that is added. So a lower reward pool eventually reduces the rewards being subtracted from the pool itself.
I hope you understand what I mean. It's quite complicated :S