tldr; only so much I can change from the original, and not all the changes work the way I want.
It is important to remember that this is a remake of the unity game by Ferdafs and there are limitations as to how far off the established path I can take characters. I'm not the one writing new scenes and I don't know where the story is headed. Mostly I'm moving the content from Unity into Ren'py and making changes that (at least in my opinion) "enhance" the play experience.
I very much agree that Morty's personality is a bit all over the place. This is due to a major change from the original Unity game into the Ren'py remake, character goals. In the original, Morty is driven almost entirely by getting "points" to go home. He doesn't really care about any of the girls he is with (other than Jessica) and is coerced into sex acts to get points. Meaning that he is almost always reluctant or disgusted by what he has to do (which doesn't match how the player feels).
In the remake, he is initially driven by points, but ends up caring for the girls and wanting to be with them. He even starts questioning if he wants to go home anymore. This second approach resonates with me (and I hope others as well, but who knows) much more since getting with the girls is my goal (as a player) too. I don't care about Morty going home, but I do care about fucking all the girls.
Unfortunately this change does come with issues. I didn't completely re-write everything and make a brand new game, but instead I adapted a lot of existing story with minor changes to alter Morty's goal. Thus, some unaltered lines just feel very out of place.
The whole game probably needs 2 or 3 more full dialogue passes to even it out, but that won't happen any time soon. I don't want to do big rewrites (that most people will never read) only to have a major incompatible future scene show up. Even then, I'm not sure it is an issue that can be fixed due to the nature of this project.
I have downplayed Summer's interest in Ethan (even more so based on certain choices) from what it is the Unity game, but I can't cut Ethan (or anyone) out entirely. This isn't a branching game (and never will be), removing characters would have a huge ripple effect across the game, and lock out many future scenes.
If I was doing the game from scratch, I personally wouldn't have included NTR type stuff (aside from Jerry getting cucked, because, Jerry). But, my goal here was to try and bring the majority of the story from the Unity game to Ren'py while improving some of the less desirable aspects of gameplay and character traits. And, not all of it works. What do you want for free
Anyhow... Thanks for the input! I hope that gives you some insight into why things are the way they are.