What is at the end of a rainbow?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

I have teeth but i don't bite. Who Am I ?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

What is always in front of you but can’t be seen?

I am a ten letters word
The first four letters have the power to rule,
Next, four-letter can be eaten.
The next three-letter represents a lady.
I can fly as well

what am I looking for?