@plexus’ The Bare Minimum captures many of my thoughts.
How much do you intend to get into REPL-adjacent tooling? Paredit would be quite a detour, as are other semantic-editing features like sexp-aware text selection. Your contribution in the workflow thread suggested heavy use of state management libs, which would be another major detour.
One lesson of the workflow thread is that REPL usage varies enormously from person to person: what devs want from it, how they interact with it, which one they use. That leads me to believe that individual-REPL-specific guides (e.g. CIDER-specific, inferior-lisp-mode-specific…) are one extremely promising direction for the community to create documentation. It will be interesting to see what commonalities can be found across REPLs for a generic REPL guide. Perhaps walking people through the bare command-line REPL available from clj would be ideal, even though it’s far from most people’s eventual workflow and lacks many interface affordances. You could, as you suggest, then point readers to specific REPLs that require more setup in exchange for features.