I'd probably ask him "Am I practicing right". That's often my primary concern. I often feel drawn to the pretty colours, fun music and mind-bending philosophy of some Hindu sects, only to reflect on why
I was drawn to them and to come back to the Buddhadhamma (as best as I understand it presently). It would be really nice for the Buddha to either say "Yes, you are practicing well, keep going" or "No, you are cultivating wrong-view [or whatever], try this instead...".
I suppose with the absence of the Buddha as a person I'll have to keep pestering you lot