Can I use rice wine vinegar in risotto?
I would not use any vinegar. You will not want the sour taste that vinegar will leave.  You will have a better final result if you just omit the wine.  If you feel like it needs a little acidity at the end add a light squeeze of lemon (or even a couple of drops of vinegar).  However, I've made risotto plenty of times without wine or extra acid...no problem!