Man... you are over thinking this.
If the 300 is on the regular tumkur highway then there aren't many turns on that road. Once you hit the highway all you gotta do is sit on your bike and maintain a cadence of 95 - 100 and watch the miles fly by. You won't need to refer the cue sheet very often.
Flats etc, depends on many factors and more importantly how you maintain your bike *while riding* and if you are careful about what your tyres roll over.
Reading the odo is important so you should have a headlamp. Also keep in mind that the headlamp also illuminates dust particles right in front of your eyes so that is a bit of a distraction. Get used to this feeling *before* the ride.
If you are an IT/Software person then think of the brevet as production environment. The code should be nice, clean and optimized when moving to production. Any/All testing should be done in Dev/QA environment. If you do circus in prod then the admins/client/proj mgr/ etc will throw you out and it might cost you your job altogether. A brevet ride is no different. I know this might sound funny but trust me it isn't.
V
@Vasu, My cyclocomp and cue sheet are together. Same light will serve the purpose.