Yes, you can clean the mouse mat with lukewarm water and a cloth. The surface is made of washable textile, and gentle cleaning with lukewarm water and a damp cloth is suitable for removing dirt. The mat should then be left to dry flat, ideally for at least 24 hours.
Unfortunately, the supplier himself is still waiting for a subsequent delivery from the manufacturer. There is currently no information on availability.
Of course it's difficult to answer because I don't know your table, but I have not yet experienced a QcK pad slipping, adhesion is very good in my opinion. With this size, I think it will be difficult to slip anyway. I have both arms on it.