Hello again FF! I'll be glad to answer everything >:)
1. I don't plan on making more than two endings: one for losing the final encounter, and one for beating the final encounter. Taiyo is meant to be simple. If I'm honest, the next game will probably also follow that 2-ending concept, and the third game will for sure have at least 3 >;)
2. I have made a note on checking the H sounds when I'm done with the coding sequence I'm working on, thank you for the feedback! I'm never too sure about my sound mixing in-game.
3. As for what inspired me to make Taiyo, it's a lot of things! But most of all, I don't think there are enough adult horror games around with actual gameplay. So few of them scratch that itch for me, too. So I decided to make my own :>
Granted, Taiyo has been on the cuter side, I was struggling to learn how to draw simple anatomy to begin with, no way I'd try drawing creepy monster girls xD
But who knows? Someday I might come back to creating horror games, I certainly would like to.
Who knows? I could even be the one to release the next big hit such as Shiro no Yakata...

Zell23 is a big inspiration.