lots of good tips and tastes… my taste: 
unity: monodevelop has been a pita for me, vs code can be set up to use with unity (including debugging!)
I’m totally fine with current spotlight (used launchbar before, but ditched it when they updated spotlight. not to say these third party solutions cant’t offer you a lot more if you wish).
Warning: spotlight made me veeeery lazy with organizing files, as every search just loads instantly. Cmd+space your best friend. launcher, calculator, etc…
I can’t stand newer finder, but use path finder instead (mostly because of finders side bar and search results, also: tabs and split window (!) ). not cheap though, last time I checked. (only drawback is no airdrop, and finder has to be running in background for timemachine to work, no big deal other than the finder icon in the bar with a white dot).
homebrew, yes.
+1 for three finger drag (!)
alt click notification center in menu (symbol most right) mutes notifications (not that I ever use that view itself)
alt click audio symbol is also handy (specially if you have an airplay device)
better touch tool has become a must for me for custom shortcuts and gestures to all kinds (!) of commands, non fullscreen split screen (expand to left/right) being the most used one… but it’s not free anymore…
Dash has been super useful for instant browsing of framework docs