Yeah, now I can say i like the program
I'd add an option that allows the program to choose one of the fields with least probability of being mined, if nothing is obvious, so that all board can (might) be solved just by pressing Ctrl+Space. And then I'd add an option for auto pressing Ctrl+Space
as fast as possible...
Also, after making a move, the capture engine could just check those fields that might have changed, if that would make the process faster.
My idea would be also to check probabilities of not only those tiles that are adjacent to open tiles. Let's imagine situation where you have just made the first move, and the number 5 was revealed. Then, the rest of the board has much less probability of not being mined, that these 8 tiles adjacent to this 5. In fact, on Expert mode (16x30, 99 mines) when the only revealed number is 2, then the probability on adjacent tiles is 25%, whereas on the rest of the tiles we have 97/(16*30-9)=21%, so your program advises a bad move! I'm not for covering the whole area with numbers, but I think writing the probability of the unstable tales would be good.