As for run times this chart was compiled from the feedback of several dozen racers in America's most active RCforum and averaged on an excel spread sheet to give some good approximations.
http://www.oople.com/forums/showthread.php?t=37230
These were American tracks so for European tracks and what I have read from other people commenting on OOPLE about their run times; I'd figure Euro averages to be on the upper end of the mah/min spectrum. (Higher mah consumption due to faster bigger tracks)
In the 4s category for example the average is around 240mah/min on tight tracks without extreme conditions, I run 280mah/min avg. in extreme heat on small to medium tracks personally. From Everything you told me, you would be between 270-320mah/min if you drove in hard race conditions, giving you 15-17min at most.