So does that me that coppia is more for relationship couples (exactly 2) and paio means more like a few (of non matched) things. IN English, the latter context may not be exactly two, eg I went out with a couple of friends- could be 2 or 3 or even 4. Is that the correct usage in Italian?
Usually it's fare una domanda, fare un paio di domande, but chiedere domande or domandare domande sounds really unnatural. it's grammatically correct but sounds foreign (i'm italian, on a friend's account)
mmm .... Saresti riconosciuta come inglese ; ) Anyway you can try a little experiment: from google search type "posso chiedere un paio di domande" (4 results) and then try to type "posso fare un paio di domande" (1.590.000 results). Ciao.