Angle sensor threw on mine when the 12v battery was weak. Its the airbag rollover sensor and is $1k to fix, if the code won't clear.
"BCM low voltage" literally means the 12v battery is low.
I agree with Leftie. I'm 99% sure this is a low 12v battery.
Do go charge the 12v battery, preferably with an external charger. Then try to clear ALL the DTCs. If any won't clear OTHER than the TCU, there's a problem.
The TCU code is normal and means the car doesn't have the 3G carwings upgrade. Ignore it.
If you buy this car, charge the 12v with an external charger for a while and check the voltage. If the voltage is low, buy a new AGM 12v battery.