Are these sentences OK?

You interfere when you shouldn't.
You're meddling in when you shouldn't.
You're sticking your nose in when you shouldn't.

Question

Are these sentences OK?

You interfere when you shouldn't.
You're meddling in when you shouldn't.
You're sticking your nose in when you shouldn't.

Answer

In #2, eliminate "in". In #3, replace "in" with "where".

Answer

Yes

Answer

Yes, they are okay. I agree with Dan, however, that the second one is a bit awkward. I would prefer "You're meddling when you shouldn't."

Answer

The basically all mean the same thing.     To me the second sentence sounds incorrect. If you say 'meddling in' there needs to be a direct object,       So either:

You're meddling.              OR
You're meddling in other peoples' business.   etc.

Answer

Yes, all of these work.