In general you want to average 1 footcandle (roughly 10lux) over the area and never less than .1fc (~1lux). However, I have yet to see an inspector with a meter... Also be aware that the size of most auditoriums makes them tough to light.
We spent over $5k working with electricians / architects / and the "lighting consultant" bringing our newlobby up to code after the consultant used the NFPA requirements instead of local requirements, and yes the inspector walked around with a meter in every square inch of the lobby, severral times, with an attitude, and a finicky meter.
Huh, that's tough. Our inspector (Fire Marshal, actually a nice guy) just made sure they stayed on for 90secs, but wouldn't go out onto our FOHcatwalk. Hmm, I don't know which is better, knowing you're covered, or less strict rules...
From what I understand < read that as "I'm not a licensed Life/Safety expert".>
Aisle lighting is seperate from egress lighting. Egress is what must be present in the case of a power failure / disaster. Aisle lighting must be present when a room is occupied but use demands darkness otherwise.
I do believe the coverage on the floor mus be the same, however.