Are you guys serious right now? you can already do this in game. its called a macro. /item "Item Name" <t> boom you're done. i hit Alt+4 and i throw Paralyzing Potions onto the Ogre, or Alt+5 to throw a Fire Potion onto a teammate or myself. if you like, you can change the <t> (target) to <me> (yourself)

I do however agree with the lack of stronger potions though there are elemental potions that heal for a different amount depending on your elemental alignment.