M - I totally understand where you are coming from in terms of a manipulative H. Even if an issue was clearly my H's fault (i.e. when I found out about the A), he managed to turn everything around on me to the point that I left the conversation devastated because of his manipulation. Since my H can accept criticism, he is the master of turning everything around. In addition to not having your concerns heard, you are then personally attacked. I get it - it svcks.
Unfortunately, you are going to be in the person who needs to stop this pattern. Because lets face it, your H is going to continue to bully you in this manner because it has worked in the past. As much as it is unfair, I think that for the moment you should ignore all the crap that he put into his email. Even if you point it out, it will get you no where. And I am not suggesting that you need to roll over and take this forever. I just think that you need to stop what you were both doing in the past and try to get to a place where your H thinks, maybe this is not working. It already happened a few weeks ago when your H threatened you regarding the divorce and you did not engage. He then came back and tried to be nice. He is expecting you to come back with an angry email. He wants to get you riled up to further justify his current actions.
If you ignore the tone of the email, your H has some valid points that you may even agree with including the fact that you that you dont want to shelter your kids and you probably dont want to let them quit just because they dont want to do something). My guess is that you and your H are probably on the same page on a few issues and it is just his tact that is very upsetting.
Where I think he is wrong is with respect to your D being car sick. I don't see that as her "needing to overcome adversity." It is a medical condition. Sending her on a million car rides is not going to cure her of the condition.
My H used to get annoyed because I am cautious about places where we stay because I am very allergic to dogs/cats. He thought that I was inflexible and should just have fun. What he failed to understand is that having an allergic reaction is miserable and not a choice. I try to take medicine to manage it but it does not always help depending on the dog. So yes, I try to avoid situation where I know that I will have an allergic reaction. It has nothing to do with fear or overcoming adversity or being inflexible. I just dont want my eyes to swell shut and have trouble breathing...because that is not fun no matter what I may be doing at the moment.
With respect to the field trip, what is the main reason that your D does not want to go (not your reasons or your H's reason). Does she not want to go because of the car ride and getting sick? Or did she mention other reasons? Maybe go back to her and ask her to tell you again exactly why she does not want to go.
If your D does not want to go because she is worried about getting carsick and not having you all there to help, then I would tell your H that you and your D would be okay with the field trip if your H went along (I know that you cant drive, but is there anyway that you could go and not drive in the alternative)? If this is the main reason, then you can explain that it is a medical condition and does not have to do with overcoming adversity.