Can the popup for a ability in hotbar....
 

Can the popup for a ability in hotbar be changed to include how much Power it needs as well?

So if I want to know how much power a spell takes i dont need to right-click and examine them each to find out?

No.

All of SOE's pop-ups are hard-coded, we can't access or edit them. What they give ya is what you get, unfortunately.

The hotbar uses the same setting as the knowledge book. So in options set the mana use to show and you will see it when you mouse over the icon on the hotbar.