Reinforcement of some of the comments already made.

Determine which things you are still weak on and make those part of your routine. As a beginner, flying the landing pattern and doing touch and go's should be part of that routine. Be sure to land from both directions. I occasionally encounter a person who is so uncomfortable landing from one direction or the other that they actually choose to land with the wind rather than have to make an uncomfortable final approach. Force yourself to practice things you are uncomfortable with until they become second nature. Many people think loops and recovering from stalls and spins should be part of the basic instructions for beginners.

Determine what it is you want to do. There's absolutely nothing wrong with taking your plane up in the air and flying around in circles, if that's what you enjoy. When the field is busy, that's a major part of my flights because I don't want to tie up the space over the runway, and I want to keep my plane away from planes that may not be under full control by their pilots. I save my practice/skill building sessions for times when the airspace is quiet.

Try to understand why you are nervous doing things with your 4*. If it's just because it's your new baby and you don't want to crash it then time, and building more confidence, will help you get over it. If it's because you keep doing things that lead to a near crash then you might want to spend more time flying your trainer. As has been mentioned, your trainer is capable of quite a bit, go ahead and push it. It's natural that the 4* takes more work on your part to fly than a trainer. This is part of moving to more advanced planes.

If you think you want to compete in aerobatics, or just want to do them for fun, look up the requirements and start learning the different maneuvers. See if someone in the club who already competes would be willing to take you under his wing to get you started with each one. This person will help you understand how to make the maneuver, and can correct any mistakes you make before they become bad habits. When I learned, I was fortunate enough to have two instructors, one of whom competed in Masters pattern. I learned quite a bit about airplane setup and smooth flying.

I don't think being buddy boxed is a requirement, but that's just my opinion. An important part of learning to fly is to develop the self confidence that you can get yourself out of any situation you get yourself into. One important aspect to this is when you are first learning new things, do them while the plane is 2 to 3 mistakes high. The point to flying something like a trainer or 4* for the first few planes is that they will not get into any situation that is hard to get out of, as long as you've started with a reasonable amount of recovery room, and have learned the basics such as loops and stall/spin recovery. I think being buddy boxed can delay developing self confidence. However, others find it very helpful because they are afraid to try new things for fear of crashing. Decide for yourself which way you think will work best for you.