If you can see the area lit by their headlights, then you are probably close enough to dim your own.
Because - as you overtake the vehicle in front, high-beams will be reflected straight back at the driver - through their mirrors. Low beams are angled more towards the ground.
Keep your headlights on low beam.
You should only overtake if it is safe to do so.
In practice, It is acceptable to increase the speed of your vehicle over the legal speed limit to pass or overtake another vehicle. Legally, it is not permitted. If the other vehicle is already at the speed limit, you should not be passing it. If it were a police car you were passing, at any speed above the speed limit, they could stop you.
300 feet
No. If the vehicle you are passing is going at the correct speed, why should you need to overtake. When overtaking a vehicle you should ensure there is enough clear road ahead of you to pass the vehicle without over speeding. If this is not the case you should not attempt an overtaking manoeuvre.
You should use your low beams to avoid blinding the driver ahead as you lights reflect in his mirrors.
You should dim your headlights within 500 feet of the car in front of you. The rule of thumb is, if you can see another car, dim your lights.
For a country with right side traffic you should as a rule overtake a vehicle on its left side. But on a bicycle it's allowed to overtake on the right side as well.
at least 2m
No, they cannot. A continuous white line means that no vehicle should overtake another, especially when one is turning.