I don't think you'll ever get a wait or sleep command for shortcuts, as it is considered a step towards botting. So, don't use external tools to get this effect.
I agree that it is a bit tedious to cast multiple buffs, and maybe future changes to spell mechanics will allow to queue spells, similar to the upcoming combat moves LigH mentioned.
There are several very useful applications for multi-line shortcuts, though. You can switch entire sets of equipment, or consume a suitable group of food items and potions. Maybe you need some items only for specific actions, so you can equip them with the same shortcut.