Wow. I'd like to add something more.
I've been reading the musicals pamphlets these days. In all of them there's a Naoko's message. She was so excited with each musical, not only that, it's her favourite version of Sailor Moon.
But what I wanted to add to the list of influences of Sera Myu on the franchise is what I found in the Amour Eternal pamphlet. There, Naoko says that the wonderful world of Sera Myu, with its catchy songs, the sparkling choreographies, and the addictive magic of that world (the Sera Myu atmosphere) was the inspiration to make the fourth arc in the autumn of 1994.
Now I understand why she chose a circus as the new villains. Maybe she thought It would fit in the musical format. Perhaps the Three Lights were singers because of it too??
It's crazy because the manga, which is considered the original version was heavily influenced by its adaptations (90's anime and Sera Myu) and not the other way round.