You're probably more senior than me, I figured 120 is about what a senior level employee would be worth. Generally speaking of course. Big difference for example, between expert Python dev and expert C++ dev writing display drivers or graphics engines.
I don't know exactly what I'm "worth" so that's why I like to ask around. I base what I'm worth off more the going-rate than I do me being a touch below or touch above the average employee. I'm not confident enough to demand 120 yet, but 120-180 is what I'd ask once I'm dominating interviews and able to pretty much make everyone else look like a fool.
I've found the same things on all your points. If anyone else wants to add in more salary datapoints please do so. Don't be ashamed of lower salaries, I have friends who work for 70K a year as C# devs and know full well they can make more. They choose to stay because they're comfortable. That's worth a lot too.
I make 90K now, but I work from home and am very comfortable. I know I can get 100K if I switch jobs and start going into an office again. It's not but may once I find the right place to land.