I feel like an idiot

I
assumed that because the power button on the tv was a momentary switch and that holding it down would simply turn the tv off and on, so I didn't bother checking:o
Ok so I can hold down the button and power the pc and tv on and off via the pc.
Which leads me to my next question; Since I can hold down the button on the tv couldn't I just replace it with a standard on/off button/switch?
Also if I want to have a master switch which controls power from the wall into the cab is there a certain type of switch or a certain rating I need to be aware of before buy one?
For example, I have an old power supply that I gutted for parts and that included an ac male connector:

and a toggle switch like this:

The male connector says: 10A 250V,
the switch says this:
5A 250VAC
10A 125VAC
7A 250VAC
That would connect to the cord from the wall.
Inside the cab I would have another male connector where the smart strip would connect.