XMonad has most of the features you’ve listed though: window swallowing, fake fullscreen (other solutions exist: tabbed layout, fullscreen…), xresources (other solutions exist, just not familiar of them tbh), scratchpad, tags, taffybar and many more features in xmonad-contrib!
What about dwm makes it a more appealing choice compared to XMonad? (Excluding the C vs Haskell argument)
Another (new) Emacs user here, I managed to reduce Emacs startup time to 0.6s - 0.5s on my garbage hardware. Some Emacs users have even manages to reduce the startup time to 0.3 - 0.2 seconds!
Also, launching Emacs in --daemon mode makes creating new frames instantanous and because of it you won’t experience any form of lag when using Emacs!
If you are an Emacs user, then I suggest you try out Ement.el!
Congratulations to the openSUSE team/contributors for helping maintain this wonderful project! 🎉
Only if simplex-chat had better UI…