Tarantulas can kick hairs whenever they want too. It's not always a stress or defensive reason as to why they kick hairs. Tarantulas can just kick hairs on a whim if they feel like it. This is nothing to worry about.The only time I open the lid is to water and feed it. I never mess with it. I don’t know why it’s kicking off hairs.
You need to add more substrate. They usually want to burrow at this size, so that would explain the stressful hair kicking. A hide would be much appreciated too. Some will stay out in the open anyway but they still need the option to hide.
That's no good at all, you need at least a few inches of dry substrate, a hide, and a water dish.