The minimum voltage is 3v/cell. You don't want to discharge mor ethan 80% of teh lipos capacity, so it will take a cutoff more like 3.4 - 3.5v/cell (10.2 - 10.5v for a 3S). You'll get better life from lipo if you don't always discahrge to the cutoff. Operating that way, you won't see very good longevity.
With the voltage on the screen, just re-charge when you see it get to 10.5v. I run a 3S 3300mah lipo in my 3PK and the voltage comes down pretty slowly, its not going to suddenly drop below min voltage in the middle of a race or something like that. You'll have plenty of time because of the voltage info on the sreen.
You're being overly cautious.....