I use these settings to clear all visual clutter. Basically looks like Librewolf then. For privacy related settings I check Arkenfox user.js and add the ones I find useful and don't cause breakage manually (but going thoroughly through settings already does most of it).
In a more perfect world, all of your "Remove *" items would be implemented as extensions that come pre-installed, and this process would be as simple as opening the Add-ons Manager on a new install, doing a Select All, then hitting Delete.
Remove FF sync:
identity.fxaccounts.enabled
Remove recommendations in Extensions:
extensions.htmlaboutaddons.recommendations.enabled
Remove recommendations Side panel in Extensions:
extensions.getAddons.showPane (add +set to false)
Remove VPN Promo and More from Mozilla in Settings:
browser.vpn_promo.enabled
browser.preferences.moreFromMozilla
Remove Pocket:
extensions.pocket.enabled
Remove Focus promo in private tabs:
browser.promo.focus.enabled
Remove persistent topsites (facebook, amazon, etc.):
browser.newtabpage.activity-stream.default.sites (clear)
Bonus:
Pinch to zoom only:
mousewheel.with_control.action (1)
Full screen video like Safari:
full-screen-api.macos-native-full-screen
Calculator in tab bar:
browser.urlbar.suggest.calculator