Rabid,
The old grease pencil mark(chinagraph pen) on the windscreen should have been explained about lesson two in your flight training. It is the basis of all approaches in helicopters. It is related to the concept of a constant angle approach....keep the dot on the target and adjust apparant rate of closure and you will fly a constant angle during the approach. At the end of the approach....the target of course must slide under the aircraft but for almost the entire approach the dot on the target works a treat.
Sometimes a change of instructor can be beneficial as we all have things we teach better. A different instructor may have the ability to teach you autorotations better than your current instructor. No slight to your current guy....but sometimes a change is good.