hi
as i remember of my job in a mastering studio, you may consider the mechanical restrictions of lathe cutting...
Don't play with "out of phase" effect (especially on low end)
Don't expect something under 30Hz
Don't expect something over 15-16KHz
The lenght available on a side depends mostly on the level of the cutting, and on the amount of low frequencies. You can basically do a 30 minutes side, but the level will be something around -12dB, forget it for Rock'n'roll, but it can be ok for Classical, or quiet music...