Cascading already means something in CSS (hint: the C means "Cascading", that quite strongly suggest there is a concept of cascade in it). And I'd like to see what problem you have with CSS inheritance: if an element inherits a property, then it gets the same (computed) property as its parent. That seems pretty simple and straightforward, and a good match for the word "inheritance".
> Inheritance at the class level would actually be useful (and is another glaring omission).
What does that even mean? Do you mean mixins at the block level? Overriding rules? Classes are just a type of selectors in CSS, where would inheritance fit in anything? And if you can inherit classes (whatever that's supposed to mean) why couldn't you inherit ids, attribute selectors or pseudo-selectors?