There is no ISV on a G40, you probably mean the aux-air valve which is used when the engine is cold and closes off when it's warm. Why would you want to leave it unplugged? I can't imagine you're going to gain any usable space by removing it. I think you'd have running issues when the engine is cold but it would probably be usable still.
You wont be able to turn the crankcase breather it's an interference fit so very tight. You'd need to remove it and hammer it back in at a different angle, it'd probably also mean replacing it since it wont come out without a fight (in my experience). I think it needs the outlet to be pointing upwards though so it lets vapour out but not liquid, I'm sure you'd get away with angling it a fair bit though. Then run a 25mm pipe from it to a catch tank, don't use a smaller pipe or you'll be restricting the breather and a turbo converted g40 breathes heavily. I'm also in the process right now of adding a 2nd breather to mine from the cam cover and getting a new catch tank made up (which is being a pain because many fabrication shops are closed).