This all sounds cool.
Phase 0 and 1 would be much more powerful though, if the idea of a persona was supplemented with the concept of a memory bank. That is, you can write a little character sketch to describe how the bot will behave, but you can also use a topic, topic category, category or a set of tags to define what the bot knows.
In forums where some people know a lot or can be canonical on a subject, and other people ask questions or have less-informed discussions, this makes a big difference. You don’t want the bot rehashing old or confused discussions on a topic… you want to be able to constrain it to a validated set of facts.