Your machines are on when they don't recieve the redstone signal. I'd like to have a config option for inverse behavior, so they are on when they do recieve a signal. Or you could make this mode be able to switch in-game.

No, sorry. I think this is unnecessary as you can just use a Redstone Torch in your circuit to invert your signal.

I know about the torch. But this is an easy thing to add. OK, I'll change it myself then.