Hi Brian, again the listing of the faults all point to a battery voltage issue - as I said, extremely sensitive to voltage fluctuations. As I am sure you are aware, in a Modern XK, the battery's ability to start the car is no longer the best indicator of a good battery in situ.
In my own case, even if not using the car for a few days, I get it hooked up to the battery conditioner, which in my case is preferred the Ring Automotive Smart Charger type RSC 612, but others prefer the Ctek option.
Unfortunately you need to get your car to a suitable garage, one that has access to the Autologic or Jaguar Diagnostic equipment as I suspect one, or more, of the electronic modules has corrupted as a consequence of the dead battery and will need to be reset. Obviously with a seized brake calliper, the car would need to be recovered either on a flatbed, or by a raised rear tow dolly.
Before that, try a "Hard Reset" of the car / battery. Disconnect both leads from the battery terminals and then touch them together - capacitance discharge. Wait for around 10 minutes and then reattach the leads to the battery and see what the car tells you. If it comes alive, try and take a 10 mile drive without adjusting anything - even window settings - as this allows the car to relearn its modes.
Good luck.
N6 JMX