I've generated patches for takeaways (1) and (2)

Patch attached to previous message:
  Corrects sql-mode help about escape character syntax

  Changes the example from the incorrect use of
  punctuation rule, to the escape character rule (Bug#37459).

This patch:
  Adds backslash as escape character to mysql syntax-alist

  In MySQL syntax backslash denotes an escape sequence.
  This change adds backslash to the syntax-alist of
  MySQL in sql-mode as per (Bug#37459).