1- There is true religious zeal, and there is the zeal which masquerades as kaanus LaHashem when it really stems from the yetzer hara. No need to go into detail motzai tisha ba’av.
2- See #1. True Torah and true humanity are one and the same. The problem is when the yetzer hara presents misguided zeal.
3- By peeling away, I do not mean discarding. Although – sometimes there is chitzonius which is narishkeit and should be discarded.
4- By that, I was actually referring to all people, not just Jews.