Just a couple of questions

So I have 2 questions.

https://prnt.sc/l1xx2l

As you can see I made a custom saddle, for my megalosaurus, you can see it has some physics in some areas, so I was wondering how I could make this areas protect the rider? like blocking arrows, spears and that kind of stuff.

The second question involves the taming method of some new creatures I want to add. So what Im trying to do for this new animals is to make the adults untameable but with the younger animals being tameable, if I recall some mods had this function but I was wondering if someone could help me to add it into my new creatures.