A 1080ti would be ideal if you want 144fps consistently, I only get around 70-80 with my 1070 at med 1440p (Should be a bit better optimised closer to launch though).
No, income would just be entirely from transaction fees at that point (That is my understanding at least).
Not profitable to mine BTC with gaming cards, it was primarily Zcash and Eth that was mined (Among other Alt coins).
Would function, but would be much better to go for a CX or CXM (A 2017 model that is). A B350 motherboard shouldn't be that much more expensive also and would give you ability to overclock.
It's not really a vote, more like a public opinion poll. It has no legal weight or obligation involved, politicians can technically do the opposite of the outcome.
It would probably be better to wait for Volta since you have a 1060 (That will be fine until then), but no real need for a bigger PSU for a regular model (I guess if you want a lightning).