Q&A for How to Ride Downhill on a Skateboard

Try to avoid them! Don't turn too sharply, because that's dangerous, but check the hill for any debris you can remove and anything you need to avoid before riding. Don't ride on surfaces that could potentially be dangerous. Take it from me, I broke my arm riding my skateboard.

Loose trucks will make your turning faster and sharper, but not so stable. Tight trucks are really stable, but turn slower. It's your choice, it depends on how well you can balance.

The vibrations of the board combined with putting of all your weight on one foot while peddling will cause your foot to start hurting.

The bigger the wheel, the more stability you gain, but the less agility you will have. I would start with larger wheels.

Depending on what you mean, the best way to increase duration is gain more speed. Or you could buy better bearings and bigger wheels.

Get comfortable with riding in every way possible first. Then find a smooth downhill (not very steep) and start with glove down slides first. Once you get the hang of it it's actually pretty easy.