Can I use rice wine vinegar in risotto? I don't tend to keep any white wine in the house for cooking and have a bottle of rice wine vinegar to use up - only used it once and don't know what else to use it for. 

Could I use rice wine vinegar at the start of cooking a 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!