1. My original thinking was to keep the game simple for casual players. But now I see that there are many who want to get into more depth :) Will work on it to make the rules of the game clearer and give an option for more visual indicators.
For now, here are some explanations (which might beg more questions):
influence - at the end of each turn, the average color of a tile's neighbors is calculated, and the tile gets 30% of that color (retaining 70% of its original color)
threshold - once a tile gets 50% of the way to max-blue or max-green, it gets a dark border and is not selectable. 0% is white.
2. I originally thought about square tiles, but then it would be more complicated to figure out the 'influence' on diagonally adjacent tiles. Hex tiles eliminates that issue.
3. There is a strong 1st mover advantage in this game. To compensate, the 1st green tile is actually at 55% color. I tried to balance the game so that hard AIs on both colors would roughly capture equal number of tiles.
Glad you're enjoying the game!