2. Power switch is unneeded. Short out connection with screwdriver, then mod BIOS to start automatically on power up, then you can use the switch on the back of the power supply.
when you say short out , you mean the power pins in the motherboard? i.e. could I use a jumper and leave it there? I always use something metallic to power it on, but if I could leave a jumper there, it would be easier
Sorry, not sure.
I wouldn't leave it shorted out, but if you enter BIOS you can set it to boot up automatically when it receives power, so that way you can use the switch on your power supply or on a power bar.
Click on Settings > Advanced > Power Management setup, and change Restore after AC Power Loss to Power On. That way, your miner can restart itself if there is a power outage. Plus, no more needing to short the power pins to get it to boot. Now you can use the switch on the back of the power supply for mining to turn your mining rig on and off." from here:
https://www.pyramidreviews.com/cryptocorner/building-an-ethereum-mining-rig/