When you say someone has "the right stuff" you are saying that they have the necessary or most effective skills, words, or actions needed for the job.
The meaning is that it is the right time to do something.
you got it right
The idiom 'on the dot' means at a precise time or right on time.
"To be" is not an idiom - it's a verb.
Pest is not an idiom. It's a word.
The idiom "apple shiner" means the teacher's pet.
The meaning of the idiom in the pink of health means being in good health.
If something is under your nose, you'd see it, right? It means that something is right there, in plain sight, obvious to everyone.
It's not an idiom - to cope means to deal with, or to handle
The idiom means impress someone is egg on
"Old hand" is an idiom meaning having lots of experience.
It is not an idiom. It is an expression. The difference is that an idiom's meaning cannot be derived from the meaning of its individual words. In the expression wolfing down food, the meaning is clearly derived from the meaning of the words, and people have been saying it for hundreds of years.