Your message is a list of why you want to practice solo. The hard reality is you are not likely to get very good.

Show me a good figure skater that does it all on their own without coaching. Doesn't happen.

Show me a good boxer that learned how to box on their own. Doesn't happen.

Piano player, OK there are a few remarkable people out there that it just comes natural but for the vast majority they had lessons and critique.

When you are flying pattern, you are so focused on flying the airplane and working the sticks, there is just too much of the big picture, and little issues, that you miss. And then there are the really bad habits that always seem to creep in that you miss flying by yourself, that someone who isn't having to fly the plane and working the sticks will see. Even someone that is in a lower class will see stuff.

I've seen people improve more in a weekend than they improve in two years with some good coaching.

I fly mostly by myself, and rarely get coached, and it shows.