Eternal isn't an idiom. It's a word. Idioms are phrases that seem to mean one thing but mean something else.
That is not an idiom. It means exactly what it says, that someone was roused to eternal wakefulness. You might need a dictionary instead.
This is not an idiom. It means just what it sounds like it means -- somebody was roused into eternal wakefulness. You just need a dictionary, I suppose.
An idiom misuse is to use and idiom in a wrong way that doesn't make sense.
It is an idiom, because it does not use the term "like" or "as".
Life is not eternal so enjoy it while you can.
The idiom, at sixes and sevens means that you are in a state of panic, confusion and uncertainty. You could use this idiom in a sentence by saying, she was at sixes and sevens as to whether or not to tell her best friend that her husband was being unfaithful.
My cousin's current favorite idiom is 'as nice as spice'.
yes
This is not used as much as it once was, but people will know what you mean if you use it; it's not obsolete.
No. There is an idiom Spring into action, meaning to get active immediately, and there is an idiom Spring out, meaning to appear suddenly. Use one or the other.
It depends on how you use it. If you mean literal colors, then it's not an idiom. If you say something like "It's all there in black and white," then it's an idiom meaning that something is printed.
He declared his eternal love for her.The bond was eternal.