They are all there available to your disposal so you can abuse all the commands you want
Everything that there is in the MAIN MENU (top menu) are located in the Main.sublime-menu file
Location: %appdata%\sublime text\packages\default\Main.sublime-menu
and to answer the question just for the hell of it,
<item caption="&Swap Case" command="swapCase"/>
BONUS: if you want to add anything to the "right click" (context) menu then the file is: Context.sublime-menu same location above.
If you want to add anything to the TAB right click menu the file is Tab Context.sublime-menu
Just remember that any changes to these files will get lost when you upgrade, so if you do change it, whenever u update have that in mind