Make available spells somehow castable from the main window

Maybe you have a vision in mind already for something like this, but it would be great to have a quick way to cast spells that are not currently on cooldown.  I'm thinking maybe as a line item in the Key Areas window with individually clickable links, something like [F] [R] [FS] [RP] for the first 4 spells if all available, refreshing as frequently as the new message (1) does.  This would be both beneficial for casting things quickly during boss encounters (don't have to open a new window to cast spells while not missing out on boss hits) as well as for leveling if you're trying to cast as soon as available.