I'm very much all for improving the security and privacy of the internet and my computer, but this seems pretty over the top to me.
> Get rid of the misfeatures that allow the problem to exist. Change the browser to never send headers that leak information by design (Referer, Cookie, Etag, User-Agent, etc).
The internet is the problem. If you want to get rid of being tracked on the internet, you have to stop using the internet. If you remove user agents & cookies & tags, you don't solve the problem and you lose some useful features. None of those things keeps your ISP from watching, nor do they stop web sites from noting your IP & requests and storing them on their end. And for anything you have to log into, there's no point to hiding headers.
> Of course, none of this will happen because the people with the power to make most of these changes derive a lot of their income from surveillance.
That's probably not true now, and it's definitely not representative of the reasons the features we have were invented in the first place. Some people really did want custom features to identify a computer's capabilities. Without headers, we'd gimp caching, and we can't differentiate between mobile & desktop, for example.
> Disable Javascript. Running Turing complete code from potentially malicious remote hosts will always be dangerous
This simply isn't possible to avoid in any practical way. Windows, MacOS and Linux run on code from a potentially malicious host, as do all applications you didn't write yourself. I mean, disable Javascript if you want, but you're also cutting yourself off from all web apps by doing that. And Javascript may have more security and oversight than anything you download from any app store, it's more sandboxed by design than binaries are.
I'm not sure why you're talking about the halting problem, that just isn't a serious concern in practice, it's a CS theoretic issue irrelevant to this thread or privacy. The major browsers will all let you kill stray JS processes.
Furthermore, because of browser sandboxing, it is possible to answer some questions about Javascript, unlike binaries you download from the internet. Frontend Javascript is not allowed to access arbitrary paths in the local filesystem without the local user's permission, just for one example. Nor can they read all cookies.