I highly suggest avoiding services geared towards activists. No technical benefit other than supposition about your operations. Also a favorite of targeted attacks and surveillance.

duckduckgo onionsite is the best as it keeps your behavior looking like other tor users.

Best to not draw attention by making a pattern of using a given searx instance.

Been browsing reddit semi regularly since atleast 2009 and have never seen any DL buttons in comments. I also found it novel.

For personal reasons you should never do this. You would likely implement it poorly even as a skilled admin if you need to ask this question about Tor. For your home system you probably want to use TorBB and maybe the onion based apt repos made for Tails.

If you would like a Tor based system use Qubes(hard) or Tails(easy). If you would like to use Tor on your system use Tor Browser Bundle(easy) or Whonix(medium).

‘View as desktop’ solves this problem

simplelogin.io for all registrations, routed to any host you trust.

Emails will be encrypted to your pgp key by simplelogin before they are forwarded.

Signal is the best protocol, however it’s implementations are eh.

Tails is the best privacy OS hands down. Qubes is good for different purposes but you can easily expose yourself in hundreds of ways in Qubes that you simply cannot in Tails.

What kind of machine details are you concerned about Javascript exposing exactly? I don’t think you ought to be entirely concerned with google having your hardware fingerprint if they have no personal information of yours to associate that with.