Can I use mugwort clay mask then glycolic acid?

I would not do it if you have sensitive skin because clay masks are already exfoliating so applying glycolic acid afterwards may irritate your skin.

it wouldn't be recommended as both of them is exfoliants. But if you use the mask just in the specific zone like t-zone and you use the glycolic acid on the other area then, it should be okay :)

Yes, you can. Just be careful that some clay masks might include some exfoliating acids already.

Yes you can. But you should ask why do you want to? Both exfoliate so exfoliation on top of exfoliation can lead to irritation and damaged barrier

clay masks can be used depending on the weather and sometimes it can be a bit drying. I have oily t zone so i apply hydrating gel mask all around the face and clay mask only on t zone. I use clay mask only once a week.