We are glad to know that you like the game! :)
First things first,
Ellie isn’t as simple as she seems :) The obedience indicator will change as you progress through the game and choose the correct answers, but this functionality is still in progress.
Melanie won’t go anywhere; there will be a chance to make up for lost time. I will post here a small game soon called “Special Fun” which is a plot fragment dedicated to a single individual character, and there you can start a kind of relationship with Melanie. But her sister... she is a serious lady, with certain interests. She’s not for Sardo.
Regarding Jenna, in the old versions of the game, before the prologue was redone, there used to be some art scenes related to what Jenna saw, but in the updated version we decided to move this content to the mansion, so that it looked like additional content, not as the main element of the plot.
Although the Arkuen mansion is in the forest, there will be explanations regarding its safety later in the plot. It is not as unguarded as it might seem at first glance. We just need some more time to finish the story quest concerning this.