will ebay ban me if there is too many returns cases opened?
They can ban you because they don't like you name. Will they? Unlikely. You'd have to have quite a lot of returns, AND a lot of SNAD returns. And even then, they'd just make your account below standard and charge you more.
The short answer is YES, you can be suspended/restricted based on the TYPE of return. This means what was the REASON for the returns as specified by your customers.