Too bad the survey had no place for suggestions. Here are a few from me:
If they want to save money on art, they should stop having quests with most of the steps using low single digits of energy. For most of the game I spend 3 weeks out of 4 with no current quest then, when a new one shows up, I finish it with, mostly, accumulated energy in a couple days if not a couple hours. After all, they're giving out 15 energy per day free (plus energy awards in other activities, and lots left over at the end of PoA) and it just adds up.
If they made every step cost 20-30 energy (as in the other two games) A) People could spend more time actually doing the quests and B) The given amount of art would last longer. As it is, I enjoy the quests in the other games but this one has so much downtime I forget the plot and the characters by the time the next installment is released.
That suggestion is mostly about retaining players, not getting new ones.
I will say the art has improved greatly over what was used at the beginning (I almost quit just because I found very few of the girls attractive). If the old art is still being used for what new players experience, I can see why some of them don't hang around.
As a final suggestion, Instead of keeping the artists secret, they could reveal their names and have "about the artists" somewhere in the forum where players who like certain art could track down their comics, kickstarters, webtoons or whatever and buy them. The artists might charge less if this game gave them, effectively, free advertising. The artists might also use their social media to send fans to the game.
Just a note: If they make it "Pay Only" the game will die in a very short time. People can play the other two games for free. If this one loses all the free players, Seasons, Leagues and Contests won't have the critical mass necessary for competition.