Best medium riddles with simple answers

Every time you stand up, you lose this. What is it?

General Custer is surrounded by Indians and he's the only cowboy left. He finds an old lamp in front of him and rubs it. Out pops a genie. The genie grants Custer one wish, with a catch. He says, "Whatever you wish for, each Indian will get two of the same thing." Custer ponders a while and thinks:"If I get a bow and arrow they get two. If I get a rifle they get two!" He then rubs the bottle again and out pops the genie. "Well," the genie asks "have you made up your mind?" What did Custer ask for to help him get away?

I build up castles. I tear down mountains. I make some men blind, I help others to see. What am I?

What goes through towns up hills but never moves?

They are twin sisters, same height; they work in the kitchen, arm in arm. Whatever is cooked, they always try it first.

A slender body, a tiny eye, no matter what happens, I never cry. What am I?

I have just one, but with eight to spare, I am usually friendly, but I sometimes act like I don't care. What am I?

I build bridges of silver and crowns of gold. Who am I?

I look taller when I am young. But as I get old, I become shorter and shorter. What Am I?

You measure my life in hours and I serve you by expiring. I'm quick when I'm thin and slow when I'm fat. The wind is my enemy.