You don't have to but it's always recommended just for added support and protection, especially over big jumps :)
No, but it's always a good idea to use them. I've been jumping for 5/6 years and I never jumped without using boots
It's better to use them. You never know what could happen😉
If you have a horse who hits the fences then yes. But if they r more careful probably don't need them.
It's not required, but some horses need them more than others