Some other ideas to consider.

1. Part of the platform will encourage decentralization and spreading the wealth. While there will always be a pyramid, it should level out more as time goes on we should see more even distribution.
2. Spammers will go away when they don't make money or the community makes it too difficult for them to operate.
3. There is going to be no inherent value. Value will fluctuate based on many factors that all end with what someone is willing to pay for Steem.
4. Value will also be influenced by outside factors that have nothing to do with the success of Steemit as a platform. People who buy Steem are investors, even if they are not directly investing in the platform itself. As such they have the power too.
5. One of the ways to make Steemit successful is to attract good writers, artists, musicians, etc. that will post on Steemit. This is a double edged sword because as a community right now major celebrities signing on could be detrimental. If George Clooney (picked at random) showed up and started blogging and was verified it could very well be the end of decentralization and spreading the wealth.

You've given me some things to think about as well. I added you to my follow list.