Currently it appears that choices only impact the dialogue immediately afterwards, but you claim "your choices will open up or close routes and scenes depending on the choices you make." Am I just not seeing it because there technically aren't any routes yet?
Correct. The MC still hasn't been introduced to the main 6 characters and so dialogue options are mostly for story flair (which will continue to be a part of the game; I like giving options even if it's not story-critical). The next public build will go up through Chapter 4 where you'll have met all characters and 'love points' behind the scenes will start impacting options for each character.
Can I say maybe? As it's a work in progress there will undoubtedly be elements I rework over time. Meaningful choices I plan to call out pretty obviously but subtle ones (at least in my current thought process) I'd rather be discovered. As an example, where you get stabbed in Chapter 1 will vary some options later on (one being partially sexah') but won't affect any route meaningfully.