Yes, that will work.
Would I be able to turn everything on this way (no Visio on this PC) or at least will my wiring work in terms of if I flip the switch will it instruct the PC to shutdown and not just cut the power:
I don't want to wire it to ignition since I don't want it power up every time I start the car hence the switch.
Yes, I know hardly anything about this so thanks for any answers
Simple, straight-to-the-point answer