Your claim that attacking a PoS coin is a "fixed cost" and attacking a PoW coin is an "unbounded cost" is similarly ridiculous considering the costs of attacking both types are dynamic (PoS depending on the price of the coin and PoW depending on the hash power of the coin.)
It is absolutely correct. Once you control a PoS coin, you control it forever at no additional (significant) cost. How can anyone else ever take control away from you since you control staking and the only way anyone else can get stake is by buying it from you? No one can and you don't need to continue expending resources (mining) to retain control as you do with PoW.
Wrong. If someone buys up 50%+ of the currency supply to attack it, the PoS coin's community thanks them for the donation, forks the coin, rolls back the blockchain, and continues business as usual.
Your very high-level conceptualizations are analogous to way Evan thinks when he is designing Dash. The flaw in your logic is you haven't even thought about the details of what it entails to accomplish what you wrote. You are broadstroking your conceptualizations without expert introspection.
The only way you could accomplish what you stated is for the system to not enforce a consensus protocol.
Your conceptualization is that you can identify who is acting in bad faith and confiscate their stake. But if you could do that in a proof-of-stake design, then it would be impossible to attack the coin at the protocol level with any level of stake. Since we we know that is not true, then it follows logically that your conceptualization is proven to be impossible. I have explained in my thread that the only way to achieve 100% permissionless security at the protocol level is with my innovation on consensus.
Either proof-of-stake is not a decentralized protocol for consensus so your point is correct, or vice versa so your point is incorrect. This ties into the point that
politics has absolute control in proof-of-stake. Does everyone always agree with the decision of the government. Who is that again who predicted DPOS would end up in a shooting war?
[...]Bitshares is going to have elements of the Roman senate, maybe people will even stab or murder each other eventually[...]
You will be unable to refute this: