It sounds like they are trying to increase their revenue/profits and think this is the best way. I get that it is hard, because when everyone is anonymous then it is hard to collect money from people. Perhaps make some way to donate/subscription for signal a la pay what you want? I love Signal and would pay for it if I could.
1. It's not a company but an NGO. Therefore, in theory, as long as they can cover the operational cost, they should be good. Of course, there's plenty of NGOs that don't do that.
3. Brian Acton (WhatsApp co-founder) "donated" a hundred million to it. In theory, that alone should keep them running for at least a decade, but the "donation" was more of a loan with 0% interest, meaning that Signal will have to re-pay it back at some point. Also, just to make it shadier, he happens to be the chairman of the Signal Foundation. So he loaned the money to the org he's in charge of.
You can use a Librem 5 in this exact way. I do it - it's fast enough to run an IDE and do some programming (as long as the thing you work on compiles in reasonable time), check e-mail, IM and social media, do some light browsing etc. I have GIMP, Inkscape, Audacity and LMMS there, which together with Qt Creator are pretty much all the tools I need for my gamedev work - and now I can do that on my phone attached to a screen, keyboard and mouse. Jamulus, Mumble, mpd, even some lighter games and emulators - it all works, straight from Debian repos. It's pretty fun.
I have even ran a full Plasma Desktop on an external screen this way - and it worked surprisingly well even despite of GPU acceleration not being available there because of a bug.
So corporations are mad because of high taxes and regulation and move to state where there is less of all the above, what else is new?
Hell, we are at the point where corporations just throw out they are going to move somewhere and states throw tax breaks at them for the promise of X number of jobs - which never ends up happening.
You can work a job you don't like as long as it fuels your other hobbies.
You can work an all consuming job and love every second of the grind and have no hobbies.
Most people find something in between.
Learn, you are lucky to live at a time (and place) when the worlds information is right at your fingertips.
Figure out your goals and then figure out a plan to get there.