Re: DECENTRALIZED crypto currency (including Bitcoin) is a delusion (any solutions?)
Most of these types of attacks end up much less profitable than simply being an honest delegate. These attacks are also unlikely and easily mitigated and/or not possible (in the case of the bolded). It is funny you are linking to them to make your argument vs PoS. You should have learned by now that you need to analyze each PoS variant separately, genius. 
I like Bitshares; it's very innovative, the community is intelligent and friendly... but DPOS itself is a failure - majority control of the network lies under one or two accounts, which are exchange wallet accounts. If these accounts decided they wanted to, they could shut the entire network down. This is not decentralisation.
If this is true, I have not checked and it may not make sense for them to try and mess with the network. They would need financial motivation to do so.
Why would they:
-Create witnesses that will do what negative actions exactly?
-Vote these witnesses in
-Prosper how so?
There is also an interesting thread on their board about the possibilities of keeping BTS on the internal exchange acting as a true share and only having the derivatives such as BitGold on 3rd party exchanges. This would solve the exchanges voting or not voting problem however other issues do arise.
TPTP_need_war: CoinHoarder does bring up some interesting points about BTS that separates it from the usual POS decentralized debate. While nothing on this earth is "perfect" it might just be one of the better options currently available. They also just rolled out the stealth transfer code that will satisfy a lot of users wanting to not broadcast their transaction details.