Yup, most of the protection is against same-frame events and events that don't make sense, but can still sometimes come through (you'd be amazed at what trackpads try to do sometimes).
That said, slowing down attacks is pretty-much an unavoidable side-effect of every other interaction system. I'm sure people will complain about that when they can select the different methods eventually
Not so sure about the right-click to attack method, as right click is deselect-glyph at the moment. Would you make right click use a glyph in that setup, how would you stop casting?