> Several of these suggestions seem somewhat disingenuous - e.g. many of them to be about free software more than actual concerns about tracking [..] None of the proprietary browsers will track you.
No, these issues are very much related. It is the very nature of proprietary software that you cannot inspect and modify it, so you cannot know if it will track you or not, and cannot fix things if you are.
(Inspecting outgoing traffic is helpful, but unless you monitor all activity all the time, and make the effort to actually understand every single bit that is transmitted, you can't be certain.)
Furthermore, some of these browsers explicitly do track you. For example, Internet Explorer, Chrome and Safari provide ways to sync your bookmarks, all of which track you - and some of them encourage you to do this, for example if you do not log in to Chrome it says "you're missing out". (Firefox also has a sync service, but it is encrypted on the client, so the server cannot read the information, and you can't be tracked.)
Although proprietary software may be easier for a government to compel to be modified to add tracking, it still runs the risk of being noticed in most reasonable cases, and there is in fact no evidence that any Western government is doing any such thing. It does increase the chance that you are being tracked due to incompetence, but I don't think this is particularly likely for such well-known software.
True, there is a difference with the bookmark sync - I do not think it is valid to discount a browser entirely based on this.
You seem to be assuming that tracking only happens either through incompetence or government mandate? Companies also track users to make money. Just today there was the news that twitter is starting to track its users, for example (at least it is opt-out).
Tracking in client-side software that occurs to make money is typically described in privacy policies, and a browser adding additional tracking would likely cause an uproar. While Firefox may provide a better default regarding sync, there is a difference between saying "stop using Chrome" and "enable client-side encryption".
> Tracking in client-side software that occurs to make money is typically described in privacy policies, and a browser adding additional tracking would likely cause an uproar
Emphasis mine. Yes, you might trust them not to track you, or to trust that someone will find out if they do, and that you will hear about it if so. But far better would be to use an open source browser (either Firefox or Chromium).
Twitter has been and will continue to track users' (and possible non-users') external web activity through their embedded buttons on so many pages. They're now beginning to sell that data, and that's what you can opt out of.
> For example, Internet Explorer, Chrome and Safari provide ways to sync your bookmarks, all of which track you
Safari is getting especially terrible. You can either sync "Safari" with iCloud or you don't. This includes bookmarks, but also ALL OPEN TABS ("iCloud tabs"). My bookmarks are absolutely harmless, my open tabs are highly sensitive. Apple sucks at services. :(
No, these issues are very much related. It is the very nature of proprietary software that you cannot inspect and modify it, so you cannot know if it will track you or not, and cannot fix things if you are.
(Inspecting outgoing traffic is helpful, but unless you monitor all activity all the time, and make the effort to actually understand every single bit that is transmitted, you can't be certain.)
Furthermore, some of these browsers explicitly do track you. For example, Internet Explorer, Chrome and Safari provide ways to sync your bookmarks, all of which track you - and some of them encourage you to do this, for example if you do not log in to Chrome it says "you're missing out". (Firefox also has a sync service, but it is encrypted on the client, so the server cannot read the information, and you can't be tracked.)