Regarding the "safe" energy levels, does anyone know how what the assumptions of the pupil size are? If the "safe" estimates are based on a normal (day adaptation) pupil, wouldn't the resulting figure be an overestimate for a dilated (night adaptation) pupil?
According to wikipedia, a normal diameter of the entrance pupil is about 4mm, ranging from 2mm (bright) to 8mm (dark), so the underestimate might be with a factor between 4-16.
The HSE document HSg95 (The Radiation Safety of Lasers Used For Display Purposes) has a section on calculating MPE levels. They recommend using a 7mm pupil diameter. This is due to most laser shows taking place at night or inside darkened venues.