The no-combat is something I read about when the game was in beta testing; someone said that most enemies you can sneak past. I also thought I remembered reading that one of the beta testers got through the entire game without combat. I don't remember where I read that now, though, so would have to look for it. If I find it again, I will let you know.
Maybe this is where I got the idea; this is from their Kickstarter page:
In fact, there’s a Steam Achievement waiting for everyone who completes the game without killing any monsters. That will be one of the most challenging of the game’s achievements.
Anyway, if I can find info that states you can positively get through the game with zero combat, I will let you know.
There's a thread here
where the developer talks about the possibility of no combat, among other things.
And I guess this would be the "last word" on the subject for now - I found this in the game description on the Steam page:
Most combat is optional for those who prefer a pure adventure game, but there are ample rewards for those who choose to valorously fight the creatures that threaten the school and all of Sardonia.