And will it be possible for an hacker to install those drivers remotely?
The hackers won't be able to install the drivers remotely if they aren't close to your device but if the device has Bluetooth connectivity and the hacker is in close distance from your device then in theory that person may be able to connect to your device and install those drivers remotely. However, you really don't have to be worried about that thing if your pc doesn't have any Bluetooth connectivity built into it.
It's not really practical attack though. Besides, typical bluetooth have either short range (10m or less) or very short range (1m or less). So it could be avoided if you don't invite someone you don't trust to your house.
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What about flashing the BIOS? In theory, malicious programs from hackers could also be installed there.
Malware which can place itself on BIOS is rather rare and i expect it have limited capability due to constraint of BIOS size. Although it's good idea assuming you know how to do it, since you might as well update your BIOS.
Networking components are now integrated into the motherboard, unless it is a very old computer in which the network cards were external and removable. How to be in this case? The Wi-Fi module is unlikely to be integrated into the board, but can the input for the RJ-45 connector just be desoldered just in case?
I'd just place "RJ-45 cover" on RJ-45 port since it's easier and less risky for average people.