Rufus or registry editing during installation can both dodge the requirement if you need it.
Tbh, there are a handful of reasons to avoid F-Droid, all of which existed long before this. AFAIK nothing with the app itself changed as of yet so I'd hold off on quitting it over this.
Calyx with Micro G does have benifits, but isn't quite as good as sandboxing, and also doesn't have some of the other degoogling and security Graphene does.
If you have the time + know how to keep up with Arch, and want the latest packages or need the latest drivers, then go for it.
If you only want an Arch install experience, then fire up a virtual machine and stick with Endeavor or switch to a stable release like Debian on bare metal.
But most importantly, if it brings you value (in productivity or experience) then whatever you decide isn't a stupid decision.
Not sure you can, unless you're using a Pi Hole. Vanadium doesn't accept plugins to my knowledge.
Do filters cancel a notification? If so you can send them to a generic folder that doesn't notify you.
And if you don't want to give them an email that matters consider simple login. It's owned by proton and will give you a few addresses for free.
Mozilla's funding comes from Google (not all of it but enough that all their other finding source's wouldn't even cover the bulk of the CEO's salery). I doubt Mozilla is going to do much.
We can hope it doesn't bode well for their ongoing anti trust case though
Clients taking it into their own hands reminds me of delta chat. Basically the same thing but the client handles encryption and uses a generic email server as the chat server.
But any good client will handle encryption themselves (heck even "bad" clients will do that). As long as they're not UK based and don't neuter the clients for their UK users they'll still retain proper encryption completely client side (outside of public key infrastructure which is a whole different topic).
I'll add one more grip: Amazon integration. It's been resolved for like 7 years now, but I still hold it against them a bit for placing Amazon search results in my desktop all those years back. Not that I don't have an Ubuntu server running as we speak, but it still does taint them a tad in my eyes (and probably acts as an anachronism to the "it's a corporate distro" theme of dislike around here).
Sounds like what you're looking for is PGP/GPG. Been around for a while, but does the job well.
Also, I doubt most projects built outside of the UK (or Europe as the EU seems to be moving in a similar direction) will actually comply and backdoor their own software. As long as you have internet they'll always be actually secure software to download.
Is it wireless? If so, and the controller supports it, try using it in wired mode. Sounds pointless, but have had issues with wireless controllers that worked fine when connected via USB.
My advice would be to look into things one at a time while also avoiding taking the sledgehammer approach. Based on what you mentioned, some things you might want to look into:
Look into some encrypted cloud storage/backup options. Filein comes to mind but there's plenty. I'd recommend against self hosting your own cloud in most cases (like nextcloud) in most cases it is both less secure and less private especially on a VPS - and if its on a home server it makes your backups less redundant.
Try doing more stuff in web browsers, web wrappers, or front ends. Unlike an app, there's a lot less sneaky stuff a web browser can do, even if it's the same platform. The Brave browser does cookie isolation and progressive web apps well, it might make a good second browser dedicated to progressive web apps. Apps like newpipe are great for YouTube and piped/invidious for yt or nitter for twitter are two good examples of front ends.
Installing apks is easier than you might think, and if you install FDroid it's three clicks (download, allow installation, install) and worth checking out. Once it's installed you can treat it like any other app store, and in combo with Aurora (on FDroid) you can get about any app without going through a Google account.
As for email, you can forward emails from a gmail account to a proton account. And as for content, consider trying to follow via RSS (you can follow just about anything with RSS one way or another).
For social media look into activity pub and nostr. Just about any alternative social media is going to have the crazies from one or both sides of politics kicked off of mainstream platforms, but federated and decentralized platforms allow you to pick and choose a lot more.
Last, as the phone goes, whenever possible try disabling background data and setting aside pre-installed apps you don't want to use and going from there. A step up from that would be to uninstall/disable them (either in settings or adb bridge for those you can't disable). Custom Roms would be the biggest leap, and the most technological. If you're going to buy a phone with the intent of installing one, Graphene beats everything else hands down while still being one of the easiest to install.
Good luck