It means you are stretching the borders. You are doing things with something that wasn't originally intended to be done.
Pushing something too far.
It means that you have made them very angry. To push someone's buttons is to "turn on" their emotions, usually anger.
It is not an idiom, it means your nose is itching.
It's not really an idiom. It means "what are you thinking about."
RFP is not an idiom. It's an abbreviation.
9 and if you really want to push the envelope 10 ...just a little humor....10
"Sieve" is not an idiom. See the related link.
It's not an idiom. It means the tip of your nostril.
idiom means expression like a page in a book
Envelope in this case is an aeronautic (aircraft and piloting) term for the limits in which it's safe to operate the aircraft. "Pushing the envelope" means doing something just a little bit harder/faster etc than what's considered safe and sensible.
The idiom "a slap on the wrist" means receiving a mild or lenient punishment for a wrongdoing. It implies that the consequence is not severe or harsh.
This is not an idiom. It is a measurement. $100,000 is how you write it in numbers.