What about my questions regarding the possibility to use this to run miners in a datacentre?
Yes.
For the rPI's we collocate the best setup is to have a powered usb hub powering the pi and any peripherals, so you only need 1 power port and 1 network cable - with 24/7 power control you can always hard-boot it (although too many of those will trash teh SD card, so we advise clients send a configured spare to be kept with their pi