1-Nope, they can change, but right now people seems to like how every girl have their own fetish, and some are waiting for these to be release to have an opinion, for now there's seeds in some LI's.
2-The Main Plot is planned to finish in Chapter 4, right now we are in Chapter 3, and this will be the longest one, after the plot is finished, will be more of a free roam. About time, it is uncertain, I'm working with a Ryzen 3 2200G, without GPU and only 6gb of RAM, sometimes it takes me 2 weeks to finish 300 renders, sometimes in 2 weeks I can do 800 renders, everything depends in the scene and how my PC works. Besides this is the first game of a trilogy that I'm planning.
3-About the personality traits of the Love Interest, these are more related for the corruption Path, for those that are playing as a Jerk that fucks everything that breathes without any remorse, there's consequences, and this is just a way to put in words that not everything is sunshinse and rainbows, the Harem Path with romance is planned to all the LI's agreeing to be part of a polyamours relationship, but in the Harem Corruption path, everyone becomes kinds of sex toys to satisfy MC, also there's a neutral path, so, it is really a very deep written game with a lot of paths without falling in a sandbox.
4-About Mikoto, his Path it is already implemented, player can choose to force him become a futa, or to stay as a male, also Mikoto can decide by himself with MC planting small seeds of the idea, this can already be played, so his path splits in two, because people really wants to play his both paths
5-About Daz, sadly it is more probably to end the game before I reach my goal, I haven't reached even my first goal to cash out the minimum that SubscribeStar asked me to have, but this is not a letdown a for me, I know the consequences of developíng a slow burn game, so I'll keep developing the game, even If i don't earn anything, because this is just the beginning and people are starting to know me.
And well, even if I reach the goal, I'll end this game with Koikatsu, so it's doesn't look weird combining another models, and once this one is finished, the next game will be with Honey Select or Daz, depending of how much I could upgrade my PC, and maybe very far in the future, consider a rework of this game.
The Game it is already in a very nice playable state with a good amount of content, but to show all his potential, maybe one or two updates more to release the real content for all the paths, my only concern is the size of the game, but I'll check on it once I reach a considerable size, I don't want it to be like 10Gb size, but well, the future is looking bright for now!