In the "Edit" Menu, every item should be about simple editing and every item should be be or contain a verb or action: This yields the following cosmetic proposal:
"Convert Tabs" instead of "Tab conversion"
"Emacs Commands" instead of "Emacs"
"Insert special char." instead of "Special characters" (the "." is to keep it short)
"Speech" could be renamed "Speak" and maybe go to the "File" or "Text" menu?
I agree more or less with the fact that a menu command should contain a verb or an action, but I don't think that this applies to submenus. The submenu is a sort of container and its name should reflect the theme or the topic covered by the commands it contains.
I'm not a native english speaker, so I can't say what's best between Speech and Speak, but the Edit menu is as good a candidate to contain this submenu as the others. It is very often the case that some item could be located in different menus for various reasons.
I agree with the renaming of the Emacs menu which is more explanatory. As to the other suggestions, I see no compelling reason to change the existing names.
Changes committed to the repository (rev. 1502 (sourceforge.net)).