That doesn’t tell the whole story, yes, long term you don’t actually burn more calories long term by exercising, but it’s part of an entire way of life that makes you healthier and you will tend to lose fat.
And studies show that riding an ebike means you are more likely to use it and exercise more, which provides a lot of health benefits, including weight loss.
Probably not, unless one is wired incorrectly. You’re just connecting hot to hot and neutral to neutral, so no power should flow.
Of course DO NOT TRY THIS. Because any mistake anyone has ever made in the electrical wiring could trigger a disaster. There is a substantially higher than zero chance you would die, and it would hurt a lot the whole time.