In the real race you get penalised for each minute over 2 hours,3 mins per minutes extra IIRC.Its over 1 hour here (without double checking the rules) There is also an absolute maximim flight time.You only get penalised if the baton holder crashes & the wingman takes over to land & thus carry on the baton(still easier than reflying a 2 hr leg!)
As far as planning goes,the general route is usually mapped out first(last year there was only ONE real way to go,usually there are more,and that makes it exciting as you se other teams veer off & you wonder if they had a beter idea!) Exact landing spots are usually left till later,dependent on weather,pilots availible etc. It used to be in the early days down to the baton pilot solely,but that has changed(perhaps for the worse it has ben said) as the rules get more complex