There's a handful of help tools out there.
http://www.buzzerbeater.com/community/forum/read.aspx?thr...The specific tools that can help with your question are Buzzer-Manager, Coach Parrot, Rhyminsimon's Training Simulator and a few others.
To answer the last part of your question. A "star" player can reach legendary in a skill. He's not limited by capping out at a certain rating. His potential, is what is capped. So say he hits legendary in one skill, his overall potential will be closer to being capped.
Someone will come along and explain this much better. There are many posts, probably pretty far back, that I can try to find if you're looking for more information.