It's perfectly fine to continue to write Android apps in Java, doing that will continue to be supported for all foreseeable future and I do it myself for a hobby app that I maintain.
That said, there are good reasons for the increasing popularity of Kotlin, it's certainly a good language that has noticeable advantages over Java.
The first movie I can clearly remember watching in a movie theatre was Mio min Mio, with a very young Christian Bale, and I've never watched it again since then but now you got me curious about doing that:
Preferably for some kind of esoteric hardware that you own but no-one else has, but it'd also be a valuable experience to do it for some commonly used piece of hardware for which good Linux drivers already exist.
For any moderately talented programmer this should be a reasonably difficult exercise, which will teach you very valuable lessons about Linux (and be quite fun at the same time).
That seems a little bit too simple to be true. How do you handle online shopping, where you often are required to provide a mail address, even though you have no wish whatsoever to receive any subsequent marketing mails?
My method is very simple, just looking for people who sit and read in trains, cafés, etc., most people who do that tend to be people who like to read books.
Moving to Switzerland.