It means that there is not enough for everyone. It's insufficient.
Do what ever you want to do.
it means go to sleep
It means to go faster
it means there is not enough of somethin to give all there a reasonable amount.
it means to take a chance or risk
This is not an idiom. An idiom is an expression whose meaning cannot be deduced from its elements. To go through fire and water for someone is easily understood to mean to make a special effort and to undergo difficulties for that person's sake.
A person needs to lose weight.
There is in fact enough Chuck Norris to go around.
It means that someone is totally surprised. They have no idea what to do or where to go, the are standing there.
"Have at it" means "give it a try". Another similar colloquialism or idiom would be, "Go ahead, knock yourself out", or "Go for it".
It's a boating phrase. Overboard means to go over the board, which is part of the boat. If you go overboard on a boat, you fall out into the water. As an idiom, it has come to mean doing so much that it seems excessive.
It means to feel that there is no way to go on and you just want to give up.