By the way, assigning for example F7 to a "My Scripts" tool shortcut key for a specific script works 
only if "show icon in the toolbar" is checked 

 you can set same shortcuts for couple of scripts but it will trigger 
only the last one which was made visible as an icon! It would be interesting to fire-up couple scripts at once but how would they share one batch i/o log?
P.S. Why not calling "My Scripts" tool a "Script Tools" (since it actually works like the PDFe Tools, e.g. "Find Duplicates...") - we already have "My Scripts" tag which denotes scripts which are not in "Library" and not "Samples" (in "Scripts Editor") and once you start working with "My Scripts" for "Edit Info Fields" batch tool, it seems that "My Scripts" tool is probably the same thing. IMHO, it takes more time (and confussion) to learn PDFe features when there are duplicate names/tags/titles.