Regarding your second point, I also thought this was a very interesting subject in the podcast. When Portal was used as an example, my ears unwaxed. I may be projecting my own philosophizing onto theirs, but I'm really interested in how a theme or aesthetic can interact with the dynamics of the game; specifically in examples where their relation seems complimentary and somewhat representational of each other. I think you may be talking more about the relationship between game space to explore and game mechanics to explore in your essay, but I focused more on their interest between mechanics and theme. If you are interested in this type of thing I think you may really enjoy this GDC talk Clint Hocking gave about where the meaning in games may lie. No pressure, it's over an hour long. If you are both curious and impatient, skip to the 14 minute mark.
About to get really far out here:
So when I take naps, I often notice that as I am half asleep, whatever procedure I have recently been concentrating on is being applied to somewhat random details of my life. An example would be that if I just spent an hour washing dishes and then I took a nap, my mind might begin thinking of ways to take the cats to the vet for their rabies shots by picking up the untreated cat, scrubbing it into a carrier, driving like hot running water to the vet and then parking at the vet the way I might place a dish to dry. I know that is confusing, I'm in the process of learning how to explain it to myself.
This tendency of my naps to mix procedure (game dynamics) with details of my life (game aesthetics ) seems similar to the happenstance way that many games dynamics have aesthetic themes placed upon them. What I would consider more successful (and what I believe the Idle Thumbs cast was referencing during that reader mail) are when this marriage is between a dynamic which represents a seemingly valid perspective on the aesthetic theme or vice-versa. Portal is often the example that comes to mind. The player is solving a series of puzzles with prescripted solutions in order to slowly test their skill. This is also an accurate description of the theme. So I have begun thinking of game dynamics and game aesthetics in a ratio type of relationship. When they match, I get super excited. I want a word that refers to this quality.
Another example which is far more ambiguous is Zoe Mode's Chime. Though there isn't a realistic association between influencing loops of music by fitting squares together and covering an area with solid blocks, the game suggests that relationship may be complimentary through it's confident execution. Its as if they are presenting me with an experience that I could believe a synthesete composer might have. I am really interested in this type of relationship, but haven't gotten to the point where I can describe it well.