I would love to hear his views on the decline of the Italian film industry, to what it is now.
It's always great to hear about it from someone who actually lived it, and was a part of it.
Also, a few misc. things you may like to ask about:
-working with Arthur Kennedy on Non si deve profanare il sonno dei morti (The Living Dead at The Manchester Morgue);
-working with Edwige Fenech on La vergine, il toro e il capricorno (The Virgin, the Bull and the Capricorn);
-working with Fulci on Murderock;
-other questions about some of his minor films, such as working on that bizarre (but fun to watch) mess that is Play Motel.