Check the PC (or motherboard) manufacturer's web site to see if there is a firmware update for the BIOS. If there is read the notes to see if you think that the fixes or improvements are worth it. Updating the firmware is doing a brain transplant so in the unlikely event that something goes wrong there will probably be no recovery.
Yes, you can probably do it, depending on the procedure given.
Yes, you can probably do it, depending on the procedure given.