2 - Name the bookmark folder (within the top-level bookmark folder) something like: 'Tab-mess-from-<date-time>'
3 - Ctrl-F4 close them. Press and hold Ctrl, then F4 them one at a time. You can close 200+ tabs in a minute. (or as other suggested, right-click any tab and use the option 'close other tabs').
The issue i find is that even if you create the perfect system, you still rarely m go back and revisit these tabs kept open.
It can make this a little better by storing the tabs as part of a task. Soo you can get back to them as part of a context rather than just a link.
As a bonus you can arrange URLs by name, url, or time next to each other, so it's usually fast to churn through related or duplicate tabs.
Ctrl-F4 shuts down entire browser, Ctrl-W closes each tab with a press of w. This is behavior in Ubuntu and it holds true for most application windows.