How does that work, if the input is higher than YoMixe's balance coin, or does it work on a versatile algorithm? Just read my question as a common user if it is a stupid one, considering I'm not tech-savvy on that part. 

This means that if the mixer take a commission from 1% to 3%, then you will get a commission from 1% to 1.5%, according to the commission that will be deducted in each transaction.