Yes, they do.

I think it's mostly (depending in the specific Version/OS) about 10 minutes default. For example, the Google Clock app lets you change the "silce after" option, with the default being 10 minutes.

Edit: I've tried to look for your specific alarm app but couldn't find anything online (and I don't want to download it just for testing), but maybe you could just download it wherever you are right now and search of there is a default option or test it?

Yes

A private YouTube client

I host https://proxigram.kyun.li and it is currently down, will work again soon :)

EDIT: Instance is working again

Privacy-wise your calls and SMS can still be spied on, and you can still be tracked by GSM Triangulation since the phone is capable of 4G.

Also afaik it runs Mocor which is designed for dumb phones, and I've read somewhere that Mocor was an Android 4.4 fork or something like that, but APKs won't start/run.

Lifehack is just to use . and , to skip forward/backwards for 0.1 seconds in a video

That's exactly what a fed would say

It's also worth to mention that you don't need a Mullvad account in order to use their Browser.

https://catbox.moe/

Mullvad and Cryptostorm

I don't think there is any federated Pinterest alternative (yet), but the closest would be PixelFed as far as I know.

Google Pixel 4a with GrapheneOS