The TC/ESP/ABS fault is common under this condition because the engine and ABS ECUs talk to each other. The ABS ECU needs an engine load signal from the Engine ECU in order to control the ESP and Traction functions. You get the same ABS faults if the MAF fails as well, which is another engine load measurement.
It's all 'driver demand' modelling in modern cars, which is heavily tied into chassis control unfortunately. Fix the engine and the ABS faults will disappear.
I'm still leaning on a wiring fault now that misfires have cropped up. VW usually send the coilpacks, injectors and throttle wires down the same harness, so I would be looking for signs of chaffing and/or breaks in wires. Perhaps wiggle the harnesses around with the engine running and see if that causes stuttering. It all seems like too much of a coincidence to me.
As I said previously, the throttle body harness is/was a known issue, as was the throttle body itself, although I believe the latter was more to do with weak return springs on the original VDO throttle, which could cause rev hang coming off boost.