Awesome, thank you for all the links! This'll go right into my next browser session for sure :) (Did I mention I enjoy learning things and researching stuff? Cuz, I do!)
With that end, I think I will work "backwards" from there, and figure out a good wallet situation for myself. Because of how spotty internet is here in my home country of Germany (there is a famous Merkel quote about how the internet is "new territory"...and believe me, it still holds up), I am concerned about my phone losing connection, thus breaking functionality of my wallet - be it to sign transactions or alike.
Within the BitcoinCore docs, I saw mentions of "running lightweight clients", and while building I saw the bitcoin-wallet utility. Now, question is: Can I run something like a "wallet client" on my phone, whilst my real wallet runs somewhere more persistent?
I could, very likely, be misunderstanding how this works. I only just got back from a long city trip so I am actually about to go digging through documentation again. But... while I am in this textbox, I might as well ask. :)