The futures market was already pricing in the vol. It's still in contango meaning that even the farther months moved up
In all reality, you shouldn't listen to others to make your investment decisions. All you need to do is understand the product (prospectus) and know that it deals with futures, twice levered. You can make money on either side of the trade if you know what you are doing. It sounds like you aren't there yet, so I wouldn't advise you to buy or short. You can get burned in both directions.
If people can entice other people to buy this ETN, then it impacts the futures. Shorting, doesn't changing anything since the shares are already in existence.
Actually it was 14, but periods are not directly comparable due to the daily re-balancing. It's path dependent.
For example, if a series increases 10% ten days in a row it will represent a 159% gain in the underlying. On a 2x series it will be a gain of 519%. Now instead say the series made a one day jump of 159%, the 2x = 318% meaning the underlying ended up at the same spot, but the one day jump only resulted in 61% of the total gains versus the gradual increase for the twice levered series.
If backwardation holds for a while this could be profitable for TVIX holders. Usually it is a fleeting measure though, but things are looking good in the near term for longs.