I agree with most of your assessment, good write up.
The main problem though is there's a difference between trust and custodial and you use them interchangeably.
They are sometimes interchangeable. When you're trusting someone with your money it's custodial. When you're trusting them with something else, it probably isn't, but I haven't thought of everything and there are probably exceptions.
Lightning is trusted in certain ways, but it does not make it custodial
Agreed, e.g. you trust people not to make you pay miners a bunch of money in force closure fees, but you're not trusting them with your money -- because they don't have your money
I also trust them to not attempt to do a F&L on me
You don't need to because you can foil the attack through automated software (not sure if any is written though)
It's fair to call something TTP but not custodial
Sometimes, yes. But if the TTP can hit the "send" button without your consent, and you're simply trusting them not to do that, that's custody