Yeah characters behaving all over board feels like a red in-your-face ntr-flag. And yet I read here in some posts that the scenes that fall under the hard (non-incest) ntr category are avoidable.
Assuming that the game continues to the point when the NTR actually starts, there won't be any way to completely avoid NTR. There will be a "full NTR" path and an "NTR lite" path.
The way it's been explained by the developer, NTR is a necessary component of the story, and it will happen, regardless of what the player chooses. But, if the player is on the NTR lite path, most of the NTR will happen offscreen, so the player won't have to see it. Even on the NTR lite path, however, some NTR will happen onscreen.