It is actually, sometimes, normal to have high temperatures while on BIOS.
I do get higher temps on BIOS than idling on Windows. Also, 1.4v a the vCore is well within safe range. Stock CPU's can get up to 1.47v during boosting.
Check your values inside windows using a sensor suite like Ryzen Master, Hwinfo or from your board vendor.
As for ethernet, you may be missing out the correct chipset drivers.
Good Luck
The Englishman