I've been using CheatEngine to tinker with the planet values and I noticed that the max amount of reasearch for any planet is around ~1.7 mln Modifying workforce or science or growing population on planet, and the value circles back to some minimum (for the current pop).
I also found Aptitudes in the Traits tab during race customization. Values are saved the same way as it's hinted in the xml - default farming, industry, trade...etc are each 4 bytes of 50. Good is 75, poor is 25. I wasn't able to find the remaining points counter though