There has been considerable discussion about step height. Remember you will be walking in low light conditions so you should make sure the steps are comfortable to climb. A comfortable step height is in the 7 to 7 1/2" range for normal stairs between floors. In low light a shorter step might be good. It will also give you a wider tread to land on. I believe the maximum allowable height is 8", but two 4" steps would be more comfortable and safer.
A rule of thumb for designing stairs is rise + run = 17". So a 7" rise would have a 10" run. To satisfy building code, there must be a 1" overhang on the step giving a tread totaling of 11" wide. A 4" rise would give a 13" run, plus 1" overhang for a 14" tread. Both sets will feel "normal" to climb. Look for stairs in commercial spaces that have different size rise/tread and try them! Your brain knows!
In my humble opinion, all risers in one theatre should be the same height, as your brain calculates instinctively to anticipate the next step based on the one you're just climbed. Haven't you noticed when there is "something wrong" with a set of stairs? There is a variation in either the rise or the run between steps. Supposedly, there is one step in the Tower of London that is the wrong dimension so that anyone trying to escape will run down them and trip on that step.