so now my question is; what else is needed to "build an entire career"?
With everything on my list, you have enough material to last you damn near a lifetime at the very least.
If you want to learn more about the business side of magic and mentalism, track down anything Rick Maue has ever said about business. Any place you want to go, he can tell you how to get there. Just Google his name and look for interviews. He was a guest at the Magic Cafe once. Not many people tried to contradict him because they realized doing so would only end with Rick proving them wrong and making them look like a colossal tool in the process.
If you want to learn about performance theory, there's a lot of ground to cover.
Mystery School - Jeff McBride, Eugene Burger
The Secret Art of Magic - Nowlan Craver and Eric Evans
Mystery by Association - Kenton Knepper
The Shiels Effect - Doc Shiels
An Actor Prepares - Constantin Stanislavski