This very closely mirrors my experience. I bought an MMO mouse to use in Photoshop but found that it was probably even more useful after mapping forward, back, switch/kill/resurrect tab and so on. I also configured normal click to “always open in the same tab/window” and open in new tabs exclusively with middle click. The efficiency increases are impressive.
Gwern’s tips for “quick searching” (which I implement using DDG !bangs and Firefox Saved Searches) are very useful too, when you know you’ll use a website regularly, I have about 30 custom saved searches now.
Back when it still worked for most of the web (and before it became the progenitor of most contemporary browsers) KDE's Konqueror was my favourite and default browser.
It came with a bunch of built-in web search keywords that sped up your search intents (all customisable of course). Usually two or three letter prefixes, that were terminated by a colon, so you could, f.e. 'ggl: khtml history' (takes you direct to first google 'lucky' result) or 'wp: charles eaton' (search and show wikipedia's top hit for charles eaton), etc.
Gwern’s tips for “quick searching” (which I implement using DDG !bangs and Firefox Saved Searches) are very useful too, when you know you’ll use a website regularly, I have about 30 custom saved searches now.