I think anyone who writes fiction bases characters on parts of themselves. At least at first. Eventually, the more you get to "know" your characters, the less they are a part of you, and the more it seems as if they're a really close friend that you know. A handy thought-experiment is to consider the character's background and past experiences and how those shape the way they think. For instance, Braden is clearly from a well-to-do family but doesn't want friends who befriend him for his money. This simple attribute opens up many questions which can help define Braden's individuality in addition to serving as plot hooks later on. For example:
- What happened in Braden's childhood to cause him to think this way? Is he still affected by it?
- Why is he open with Zack about this? Does part of him still wonder if Zack cares about his wealth, especially once he finds out Zack's economic circumstances?
- Is this an insecurity? If so, how is he coping with it, or how did he move past it?
- How severely does this impact Braden's decision-making? His willingness to trust others? His social mindset?
You did an excellent job with Max, by the way. His character feels the most authentic, because the way he behaves is fully explained by his backstory. There is a harmony between his personality, his motivations and his psyche. Despite being a secondary character, I think many people would agree that after the chapter "Ash", he feels the most life-like of all your characters so far. (This is not a negative thing, since it just means that the other guys haven't had their backgrounds and personalities explored fully yet. Lots of potential here.)
Regarding conflict, I don't think there will ever be a "right answer". As an artist, you must have the conviction to follow your instincts and your vision for what you want out of the final product. Taking community feedback is good, because there are always facets of every work that can objectively be better, but with all creative works, it will be impossible to try to please everybody. In fact, trying to do so is one surefire way to guarantee the final product will be average with no vision.
(If you've ever wondered why so many AAA games feel soulless, it's because they've lost sight of this basic principle. The great games of the past did not need a focus group to tell them which audiences to please or which hot-topic themes to cover. The creators simply made what was best for their vision of the game.)
I hinted at it in my first comment, but I truly think you will have to make a decision at some point how committed you are to the slow-burn nature of your story. If you do commit, you will likely turn away a certain type of audience, but potentially attract a different one. As with all creative projects, it's truly very difficult to gauge audience reception, but if the success of "Our Life: Beginnings & Always" is any indication, there seems to be a certain demand for slow-burn, well-crafted character stories.
Conversely, if you're going after the faster pace nature of most Adult VNs, there's certainly an audience for that as well. I'm sure you've seen the many examples of well-executed ones in this genre.
My opinion is one of many, but I sincerely hope you will carry this project where your vision leads you. Even with the (little) experience you have, you're already creating something that stands out. So it makes sense to trust your instincts as an artist.
Keep up the good work!