@racerza
I guess you tried to customize shortcuts within internal Opera page? (for extensions too)
opera://settings/configureCommands
btw. what dou you mean by aplication shortcuts?
if you referr to chromium apps shortcuts, they (apps) are not supported in Opera,
also, there is no way (natively) to add shortcuts to taskbar like Add to taskbar chrome feature ...and I doubt that any extension can do this...not sure tho
it was before aplication shortcuts, now, in Chrome, it's called add to taskbar