No what I'm saying is that if protesting public chillul shabbos done to flaunt is is a good thing then the fact that it will anger OTD teens is irrelevant.
So the argument is really coming down to is the protest a good thing.
It seems you are not taking the OTD's into consideration, while the others are taking them into consideration.
Others are saying the protest itself is a bad thing because it will cause OTD's to go off even more. If the argument starts there you can understand why halacha has nothing to do with this argument it is a question of hashkafa and if you look at ll yidden as one and there aveira is my aveira, or do we care for our kids and don't care about pushing the OTD's away even more.
Also there is a difference of having a halachik status of pikuach nefesh or looking at a situation as so dire it is like pikuac nefesh and you should do everything in your power within the context of halacha to help with that situation.
I am sorry if you weren't explained that last point well, but it just takes some common sense to figure it out.
I believe this answers all of your questions.
(ETA: I think it all comes down to you are only looking at it from your kids perspective while others are also taking into consideration the OTD's, if you see that I think you'll be more comfortable with the disagreement here.)