Mining Stats Clarification

Hello all, I wonder if you could clarify some stats for me in mining.

First, do I understand correctly that increasing "extract power" means that I will be able to extract from larger fragment sizes without having to break them down more?

Second, "Resistance Modifier", does + mean that the laser somehow increases the resistance of the asteroid, which counteracts the "Fracture Power"? I don't understand what this one means.

Is "Optimal Charge Size" the size of that little window in which you need to keep the bar in order for the laser to be working? If so, then I'm guessing "Laser Instability" is how difficult it is to keep the bar steady without having to manage the power level back and forth?

Thanks.