Just wanted to post some encouragement! 8 )
I've been studying game systems for a long time (since that wee age when I discovered that AD&D wasn't the only way), and I have to agree with the basic concepts of where you're going with this. For example, my own system (that I haven't worked on lately, for shame), actually has 12 statistics, with the intent that there are very subtle and complex interactions among them.
I think there are a few very good points to developing a system like this:
- The extreme complexity which would kill the game in PnP, becomes a great tool, when you decide to commit the system to only be used with a computer doing all the complex calculus.
- Decreasing the number of available stats causes two problems, first it waters down the personality of your characters, I have seen numerous systems that go the STR/DEX/INT route, and the degree of variance among successful characters drops precipitously. Likewise, there is an inverse relationship between number of stats, and ease of min-maxing at the expense of character building. Using 9 statistics, even if they can be said to overlap in certain ways, adds a lot of nuance to a character, allowing you to give much more depth and personality as they develop - as well as making more progression paths viable.
- Cause and effect can gain a much greater depth as well. Avoiding falling into a pit, for example, should not simply rely on your "Dexterity". Having a statistic that represents sensual "Perception" allows an interaction where you assume there is a point of observation of the pit, as well as a point of physical reaction - and someone who is either perceptive but clumsy, or nimble but dull may fall straight into a pit that a person who was more average in both respects may have avoided. This goes beyond mere realism, directly to immersion.
All that said, I would have to agree, the "Memory" stat is going to be the hardest to work with, without it becoming either a terrible annoyance, or a gaping hole in the system that either requires boosting at every opportunity to keep from being screwed, or to drop as much as possible to gain points. Of course, insuring that it has very deep interactions with other stats insures that it can't be ignored totally (make it the primary stat modifying learning rate?), but it will work better in the context of the game if it has an overt function, rather than being totally passive.
I'll probably discuss this more with you later, I'd like to help you as much as I can, without corrupting you with specific design points from my own system.
