Hi Girk,
Lasers can most definitely be dangerous under the wrong circumstances. As you have already discovered, they can actually start fires. And yes, as Karl wrote, they can pose a significant occular hazzard under the wrong circumstances.
For anyone doing audience scanning, I would highly recommend you read two things:
http://www.pangolin.com/resguide09a.htm
and
http://www.pangolin.com/resguide09b.htm
The first one is an article that originally appeared in The Laserist magazine around 10 years ago, and has undergone some minor edits over the years. In fact, this article was updated very recently, providing a simplified approach to audience scanning evaluation.
Note that the simplified approach can only be used IF it can be guaranteed that the minimum pulse width across the eye is 1 millisecond or faster AND the irradiance is somewhere between 5 and 10 milliwatts per square centimeter. Note that I used the word "guaranteed" above. These conditions need to be guaranteed under all circumstances, even unforeseen circumstances. Also note that this generally means that you will need to increase the divergence of the laser projector. This could be done simply with a negative (i.e. concave) lens placed at the exit aperture of the laser projector.
Best regards,
William Benner