Regarding shorting, to be able to short there needs to be actual coins on an exchange so they can be sold in the first place. Most coins are in the masternodes, a lot are in hot/cold storage controlled by random holders/users, and a tiny percentage is in the exchanges, and even tinier percentage of those are being offered for shorting. Hard to make profit shorting considering the amount of masternodes you'd have to own. Of course the possibility to do so is there, but it's not as simple as it's being made out to be.

Arguments along the lines of "if that is true, why didn't happen yet" are refuted with:

1. Perhaps only I am the one who realized how to attack it. And I just described it today.
2. There isn't much incentive to do that attack, because (from what I've heard about most of the trading volume on altcoins being fake) there isn't any way to extract any significant value from Dash via shorting.