Imo debloating the apps itself is not possible. To do that, you would need to somehow decomplie them, change the code, repackage them and install them as custom applications. This might be possible in theory, but is not feasible in a real-world scenario.

I recommend the following two options:

1. Use different clients where possible. For youtube F-Droid has some alternatives. For reddit I don’t know the current status.
2. Use a VPN based solution such as AdAway. It can block requests based on target IP or Domain. But keep in mind that blocking certain requests can prevent the app from working.

For switzerland the “stem” type probably only applies to farmers nowadays. The others live in a more nuclear family. 100 years ago the graphic might have been applicable ;)

If privacy is your concern, then I’d use two different mail addresses / domains. One with your “professional” TLD (mail@johndoe.com) and one wirh your privacy focussed TLD (mail@anon.com).