Who said anything about forward-starting? For that matter, where/how do you suggest a retail investor trade them?
he asked for pure volatility (ie no gamma). Sle is right. a parrellel shift on the surface will cause the forward var to profit/lose. I think sle assumed the OP was the director of a Hamilton based firm like yourself who happens to trade VRX options everyday.
Well, when I have time I'll read a book about Warren Buffett so I can reach your elevated level of enlightenment...
Why dont you use old school calendar spread? while trading VIX futures it might be hard to "roll-over" and increase in size (in order to gain what have been lost), trading calendars on SPY or IWM slightly out of the money seems right (price falls, you gain vega + abit of delta- theta positive). Most important, you can roll and increase size more easily (much more).