Re: Finally, a reason to move the task bar
"Actually, a taskbar will be of help here since it can make you aware a browser window's still open."
a good point. There may be a way to have it display "iconless" though. I haven't tried. But if it's a top level window, it will most likely be in any task bar that has icon windows listed in it.
I run Mate with the upper panel having the CPU monitor in it. If I see unusual CPU activity, I typically kill that application and re-start it. Usually it's Firefox, due to garbage collection and being left open on 7 virtual desktops with 20 or 30 tabs for days or weeks on end. Sometimes it's something else. but if you see consistently high CPU usage, it's often a problem with the application. And if it's bitcoin mining, THAT would put a stop to it REALLY QUICK.
That, and running 'NoScript'.