Of course, you can roll every day, for a long time.... But as I have mentioned in another thread. I have a few friend who do these kinds of things...
The worst example I can give, is an aquaintance of mine, who told me he had 140g of mdma and used it all in one summer. Of course, he might have been exaggerating, but I totally believe it was close to that amount. He totally fried his brain now. I have NEVER seen him smile, or laugh, or tell a joke. He is always, ALWAYS serious. And he always looks so depressed. Absolutely no subject we can talk about would make him interested and want to join in. When he talks you cannot feel any sort of enthusiasm or passion in his voice, it's always the same tone. He doesn't care about ANYTHING. Absolutely nothing I've done/seen him do made him happy any tiny bit. You may not believe me but every day, he acts like his mother just died... No feelings whatsoever. He just seems dead inside.
So if you want to be like that, go ahead and abuse MDMA.