If I delete a message in Liftoff, does it delete it only on my end, or on the receivers end also?

I'm not sure if this is the right place for this question, but idk where else to ask.

Is there a way to log back into my account without giving FB my ID?

I have a Facebook account so that I can access links that require you to have a Facebook account. I don't use it for anything else. I have no friends on it.

I had to factory reset my phone, and now I can't log into my account without sending in some kind of id. It said I can log in from another device, but I get the same thing from every device.

I can live without FB. It just would be nice to be able to access links to it.

I installed the official Reddit app and went on it to see what the old place was looking like now. My inbox was filled with spam. The "home feed" shows subs I never subscribed to. There are so many ads. Between the ads and the the extra subs in the feed, it's hard to just scroll. I also noted a lot of spam in some of the subs. Maybe they are subs with no mods? I'm not sure what's up with that.

I understand that in end to end encryption the message is encrypted and only the recipient has the key to Decrypt it. How is the key transmitted, and how can the key not get intercepted with the message?

I'm looking for new discreet earbuds. The listening time is very important. As you can see from the pic, there are 2 different times. Idk which one is the actual time the battery will last while continually playing. 4-5 hours is fine. 1.5 hours is not good at all.

There's a box in setting called "Use Custom Tabs", but I can't figure out what they are.