This is a slang term that means fighting. Usually used with children. When two boys decide to get rough and start a fight they are rough housing. "Stop the rough housing you two".
There is no strong verb for play - played.
No, it is not an adverb. Roughhousing is a verb form and gerund (noun) for the verb "to roughhouse" (fight, wrestle or tussle in a friendly way).
It's not really an idiom. It means "what are you thinking about."
It is not an idiom, it means your nose is itching.
RFP is not an idiom. It's an abbreviation.
"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
This is not an idiom. It is a measurement. $100,000 is how you write it in numbers.
Simply its mean a bully.
The idiom your blood is boiling usually means that you are mad/furious.
"Penniless" is not an idiom. It means that you don't have a penny to spend. It's used as an exaggeration to mean that you don't have any money.