From what i read basicly Photoshop or any other editor will not be what you are looking for. If creating a circle in Gimp is frustrating you i think you should not start photoshop either. Don't get me wrong, i love it, but you will need at least some patience and feel fr it to get into appz like that.
What you seem to be asking is something with a library of premade stuff? Sothat you can use and or modify those?
If you do still considder editors i would advice to start of with downloading a bunch of brushes and put those in the presets>brushes folder for photoshop. Those may help out a bit.. (basicly brushes are premade shapes)