You raise valid and important questions, but I think the definitive answers to almost all of them are unknown, and won't be known for many months, perhaps years. Everyone is going to have to make their own calculations about what risks they are willing to take in future purchases of MTH locos at this point, and their long term commitment to DCS, as time goes on. Unfortunate, but as you say, fairly minor stuff compared with our current crises. Caveat emptor and carpe diem both seem particularly applicable right now.
The only question you ask that we know the answer to is that you need a TIU to make the WIU function.
