Don't worry, it'll be hard for a laser to burn your screen, as the white screens reflect the light. For burning, you typically need a dark colored object. Also, a good rule of thumb for laser output is each time you double the output it increase the visible brightness by approx 20%.

I agree with you, 30mw is a good choice in many applications - it is very bight - and while I'm sure some people with disagree.. it won't cause instant blindness in a careless mistake situation. Don't let that statement preclude good laser safety, technically speaking anything over 5mw is considered dangerous, but in practice I've accidentally beamed myself with 30mw and I can still see... most of the time.