You said a lot without providing even simple arguments for anything you said.
Net neutrality is the idea that no matter the content of a message sent over the internet it should be treated the same as any other message.
The equivalent for power/water utility service would be that you can use power/water for anything in your house and you will pay the same price per unit you consume.
Imagine if power/water companies were allowed to charge different prices for drinking water compared to dish washer water. Or your power company charges you a different rate for A/C than your refrigerator. That's power/water companies without neutrality.
Do you want an Internet provider charging you more for using your preferred streaming service over using their video streaming service? In a world without net neutrality that's what you will get. You will end up paying for the internet like we currently pay for cable channels. Websites will be packaged into bundles and if you want something from another bundle... To bad you have to buy the entire bundle.
Bitsquare, BitShares are good examples of a decentralized exchange.
> There's no benefit to trustlessness in settling a transaction when you're still reliant on a counterparty to actually make it for you
The whole point of a blockchain is that you don't rely on the counter-party to actually make the trade for you. The exchange happens at the exact same time on a blockchain.
> if one party's legal status means they must be given sufficient control to hard fork it anyway.
I don't think hard fork is the right concept here. Hard fork implies an entire network change; I think what you are talking about is the ability for a company to issue more shares, etc... They could be given this control through smart contracts.
Instead of having chain of trust through all these different entities trust would be instilled in a blockchain. I would prefer one source of truth rather than truth that is built up through a chain of private intermediaries.
As for the high speed traders they would depend on layers built on top of a blockchain that allow them to transfer ownership quickly while still using a blockchain as an eventually consistent record.