Aircraft Weight
Greater mass means slower acceleration/deceleration and longer distances. TODR will increase by 20% for each 10% increase in weight and LDR 10% per 10% increase in weight (factor by 1.2 and 1.1). Very few aircraft allow you to fill all the seats with full fuel.
Some manuals give take-off and landing weights that should not be exceeded at specific combinations of altitude and temperature, thus ensuring that climb performance is not compromised. These are known as WAT limits (Weight, Altitude and Temperature)

Leading Edge Protective Tape
Used on leading edges of rotor blades to protect against wear and tear from dust or precipitation. A partial loss of it can dramatically affect aerodynamic efficiency, resulting in substantial increases in power when hovering. It will also cause a slight loss in RPM during autorotation.
The most likely time for the stuff to come off is during or after flight through rain, which is just when it's needed, so you need to check it before take-off. If it looks like wearing out, then remove or repair it before the next flight, removing an equivalent amount from each blade, as it may have also been used for balancing. It will be put on in short strips of anything between 6-18 inches (so you're not flying with a great length of it hanging off) which should be removed as a whole— don't just cut bits away.
If tape comes off in flight (with a distinctive "chuffing" sound, sometimes accompanied by vertical bounce), reduce power and speed and make gentle manoeuvres while landing. If it comes off before landing, just carry on.

Engine Failure and Autorotations
This part is not meant to cover (again) the basic stuff you learn in flying training, but to offer advice that would be useful to a working pilot, who is very often over trees, or in remote places that the student is routinely taught to avoid. In short, it talks about surviving a potential crash, because you won't always find yourself over the clear areas you need for training.
Engine failure in a helicopter is detected by a noticeable decrease in engine noise (!), yaw in the same direction as blade rotation, loss in height/speed and RPMs, plus ENGINE OUT audio/visual warnings (if fitted), because there's so much noise you can't tell whether the engine's still going anyway. While speed is of the essence, there is usually time enough to verify actual engine failure by looking at the instruments while you're reducing to autorotation speed to maintain height, certainly in a Bell, unless you’re very heavy in a high hover situation, such as long-lining, where you have no time to do anything other than dump the pole.
For all practical purposes, your gliding distance is about equal to your height or, put simply, what you can see slightly above the bottom of the windscreen. If you keep your landing spot in the same place in that area, your speed watch needn’t be so critical (remember sight picture approaches?). In fact, once you've set your speed, keeping a mental note of the attitude will enable you to look out more. Loss of RPM at the entry into autorotation is more important—a higher angle of attack from the new relative airflow as air rushes up through the rotors will cause enough drag to slow the rotors drastically, especially if your weight is high or air density low, meaning that your blades will be at a higher pitch angle anyway. Get that collective down, and bring the airspeed back to autorotation speed. Then accept the inevitable, that you may hit something, so your primary focus now is to ensure you and your passengers' survival, that is, to protect the cabin area as much as possible. Of course, it would be nice to save the whole ship, but don't stretch the glide, for example, towards a clear area and risk losing the RPM, or having less control over the rate of sink. Clear areas should really be within a normal glide.