"AWD Error 4x4 issue" on the dash doesn't necessarily mean your AWD isn't working. It could be as simple as a faulty sensor or something minor. Your AWD is likely still functioning.
Dropping the screwdriver on the alternator just completed the circuit which caused the spark. I would be surprised if that had anything to do with your AWD issue. But may be related to the other code??
I would be surprised if towing is related to either of these.
Find your trunk fuse box diagram and spend a minute going one-by-one ensuring the fuses are the right amperage and in the right location. That will rule out a fuse mix-up.
As far as the error codes...
Code:
53FC- (21500)- KL30 Voltage supply
https://xoutpost.com/bmw-sav-forums/...ht-dash-4.html
&
Code:
54C6 Oil wear
transfer case - 54C6 oil wear how to reset - Bimmerfest - BMW Forums
The oil wear code simply signals you need new fluid in your transfer case. This is the likely cause of your "AWD 4x4 warning". The "53FC voltage supply" you may have to do more research on to figure out.. I would replace your fluid and clear the codes. See if the Voltage code comes back. Hopefully this helps. Good luck!