If my understanding is now correct from your insights, it would be much like a 51% attack on a PoW coin would work, they could only double spend one or a few transactions before being caught and voted out. Same with blacklisting or withholding transactions. So, IMO colluding delegates and/or hacked delegates would not be a "coin killer", as they can be voted out with minimal damage done.
As I understand Bitshares to be open source they could technically break away and essentially hardfork their own coin and install new delegates. Bitcoin has a much greater set of implementations, wallets , and developers so doing so would be much easier with Bitcoin.
From hours of research with Bitshares DPoS it appears that voting is done per client node despite what size stake they control. Is this correct?
If so this presents a large vulnerability. Couldn't someone create a botnet of DPoS nodes and control the vote?
Voting power is directly proportional to the amount of coins you own, so if you own 1% of the money supply your voting power would be 1% of the total votes, regardless of how many nodes you run.
Votes are updated every time someone sends a transaction, or alternatively there is a command/button you can use to update your votes for the cost of a transaction fee.