As to shorting oil, why throw good money after bad? Stating that you plan to make money on your oil position demonstrates an emotional need not to lose (one that we all possess) and that left unchecked will generally lead to substantial losses in the markets. The reluctance to take a loss on a investment/trade, holding on until breakeven, or far worse, averaging down is the Achilles heel of most investors. In the future, you should strongly consider cutting your losses at a fixed percentage or hedging your exposure.
Assuming oil is the bubble you think it is, then what makes you think you know when the top will occur? Bubbles experience parabolic moves that will not adhere to fundamentals and can continue far longer then anyone expects. As a reader of Piggington’s, you should be initimately aware of that.
