puni VS speed-of-thought-lisp

For working with delimiters, you might want to check out Smartparens or Puni. There are many other packages like these, but those are the two I know about.

I'm guessing the way forward here for navigation is to change Emacs' built-in sexp-navigation when treesitter is available? forward-sexp, backward-up-list, down-list, raise-sexp etc do a good job in lisp environments, and they can now work everywhere. Packages that build on these (like Puni will automatically gain treesitter-awareness.

I have never used lispy, but I have used puni for a while now, and I'm pretty satisfied with it. I am not sure that it's exactly what you're looking for since it takes a more limited approacg, but it has a lot of the same features: slurping, barfing, raising, splicing etc.

For any Lisp you want paredit or any other structural editing package (I switched to puni recently because it’s more customizable and works with non-Lisp languages too). The first three days will suck hard because it’ll feel like the tools get in your way, but once you’re comfortable with it it’ll be the best thing ever.

Afaik puni uses only forward-sexp for navigating and manipulating sexps. So if you implement a forward-sexp-function that uses treesit.el it should work without any changes.

Try speed of thought lisp and see if you like it, or yasnippet. I think it is great, I can just type acronym (actually could be any abbrev) and space and it completes, however I dislike the fact that it requires me to remember acronyms. But I do use it for some of the more usual stuff like with-current-buffer is wcb, require is r and so on.

Paredit, Speed-of-thought lisp, Helm, perhaps Lispy but I am not using it myself. I found expand-region to work really well when writing and modifying elisp. lisp-extra-font-lock if you want some more blink (and font-lock-studio). Helpful is very good to have instead of built-in help, it displays the source code by default as well as symbol properties. It is a very informative learning experience to see how built-in stuff is implemented. I am quite lazy to press extra in built-in help to see the source code, but with Helpful, you get it auto in the same window, whicih is great for learning. Seeing symbol properties is sometimes a time saver so you don't have to M-: and type an Elisp function to see the symbol properties when debugging. Learn Edebug, it is very useful built-in application for Emacs Lisp development.