I spent over 25 years troubleshooting electro-mechanical equipment and I don't know what a "terminal field connector" is, but it appears you let the battery connection fail, meaning the electrical system was at the mercy of the voltage regulator in the alternator. This means system voltage could have shot as high as 60 volts. If this is the case, the ECU and other modules probably took damage.

It is impossible to troubleshoot THIS remotely. Some of those codes imply a CAN BUS failure, again, the can be in any of the modules on that bus. I'd call the guys at the MSS and follow their advice, no local garage is going to 'fix' this.

GO here, give James and Josh a call:
https://themercedesswapshop.com/

This is the kind of thing they do for a living.