"But we also don't want him to be "king" (so to speak) all the time and dictate how we play everything. It's also painful to us to play his nonsense games all the time! Sure would be fun to actually do some fun things together and not just weird 4-year old games!"
Actually, this is perfectly normal for his age. Could be it manifests itself in an extreme way for a highly gifted child.
Believe it or not, he will grow out of it, maybe not till 6 or 7.
We've found it helpful to allow our girls to be the "queen" at times, but also teach them how to take turns and compromise so that other children will want to play with them!
Our DD5 loves Magnatiles.
We do a fair amount of imagination play. She has tons of little figures and does much creating of stories that go on and on and on!
On the upside, she is starting to write this year. So, she is becoming an author! Her latest tale is about a baby unicorn and it's great!
Good luck,
Incog
