A helmet cover is a thin fabric that covers the helmet. Most people use it to change the colour or look (like at shows if you want to have a black helmet but you own a different coloured one you can just put a cover on) or for protecting the helmet from scratchs but it's a thin fabric, any big scratchs affect the helmet.
When you say helmet cover, what do you mean? I've never seen one.
No but I recommend keeping a cover over it so it doesn't get scratched up and will stay nice for show!
I just put a helmet cover on for schooling
Not really anymore, but when I first got my Charles Owen I did! I have an old Troxel and I would wear it, especially when I thought my horse might throw me off haha! I didn't really want to have to pay to replace the more expensive helmet (that I now realize is really not even an expensive one).
I usually wear my Charles Owen Jockey skull cap every time I ride, I don't see a point in buying another expensive helmet for shows, unless you are a wealthy proffesional ahaha