I think the solution to the problem with my READ-EVAL-PRINT-LOOP is to not use SLIME-RESET, instead define the new function:
(defun slime-repl-reset () (interactive) (setf (slime-rex-continuations) '()))
This appears to work, but I would be happier my Lisp REPL could inform SLIME when it starts. What is the protocol for Lisp invoking a function in EMACS?
The problem is that REPL is started in the SLIME-REPL buffer and REPL never returns. thus there is a pending slime-rex-continuation that apparently prevents slime-autodoc-mode from doing its thing.