Dating concert pianist
You can work with two handed scales and Bach two part inventions to help gain control over both hands.
By both, I mean it isn't just that you may need to increase volume and control in the right hand but also let up on the left.
But even in popular pieces and I also find in the new age genre of music there are many written where left and right hands share melody.
As you say yourself, it is not just about giving big concerts in the Carneige Hall.
Even the famous ones play in churches, at receptions, even in shopping malls, at all kinds of events, in bars and restaurants, everywhere there is an audience.
I enjoyed your rendition of the mario piece, the second you obviously are working on getting the hand control down on.
You obviously are a seasoned musician in having the feeling of the music inside of you and having started young and with several instruments.