Presumably you can sell contracts short on HitBTC, too. But this all sounds pretty dicey. There are ways to do cash delivery (or bitcoin delivery) if there is a reliable underlying market and good liquidity, but here, there is neither. I don't understand how it can work unless they are splitting your coins into two different assets, like what BTCC and Bitfinex are doing. As long as the exchange is employing proper replay protection, they should be able to properly deliver on B2X contracts.
But that means they need to lock up your BTC, right? I mean, neither BT1 nor BT2 (or their equivalent on BTCC) actually exist as real assets. Their existence is contingent upon the fork actually happening. If the fork doesn't happen, BT1 = BTC, and BT2 = 0. If HitBTC is offering these contracts without taking these precautions, I'd stay away from them.
Is BTCC available for people residing in the US? I may be interested in getting some BT1. What do you think the chances of me getting screwed over and not receiving BTC after the hardfork?
I think you should look for exchanges that support it and then deal with them directly, almost everything on the internet is left to chance and you will have some amount of risk to bear and so be ready that it could go either way.