Your face usually turns red when you are embarrassed, so this phrase means that someone was ashamed of something.
To "fly in the face of" means to go against something. Example: Your actions fly in the face of our agreement.
Do what ever you want to do.
it means go to sleep
It means to go faster
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.
They are embarrassed
It means that there is not enough for everyone. It's insufficient.
The idiom "shape up or ship out" means either improve your behavior or performance, or leave and go elsewhere. It is typically used to emphasize the need for someone to change their ways or face consequences.
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".