Hunter Schooling Show - Is this okay?

If it's a schooling show I think you're fine. I can tell you for a big show, going down your list, what is preferable though.

You'd probably want either white breeches with white or beige knee patches or just regular tan breeches. Probably a lighter or pastel colored button down shirt that would contrast with your darker hunt coat. The boots and hair are good and since you have the velvet cover on your helmet you're okay with that. I don't know what kind of horse you have or what the schooling show you are going to is like, but I show Quarter horse and everyone I show with has the white wool saddle pads with the slot for their back number. You're okay with what you have, but for bigger/quarter horse shows if you pursue them, the number wool pad looks more polished. If you don't show quarter horse then ignore that though lol. Also with mane and tail if you braid the mane you MUST braid the tail. They both either have to be done or un-done no matter what type of show you go to. From the looks of your list you are all set though. Have fun!!

I've shown at a lot of schooling shows, and the 2 things on your list that stick out to me are the white breeches and the square saddle pad. White breeches are for dressage, or very upper level jumpers, never for hunters. You will want some version of beige/tan. Square pads are for schooling at home, only used for showing even in schooling shows at dressage competitions. I never braid for schooling shows, but that is up to you.