Another question: why aren’t AVNs with this kind of graphics and engine released on Steam? On Steam we see AVNs like Race of Life or Desert Stalker. Is it just because the game is still in development?
In its current iteration, AHITR will not be released on steam. There's a few factors involved (certain assets for example) that wouldn't allow a release on steam.
Don't think so, no. Although I have seen that a certain AVN made using Koikatsu somehow is on Steam despite Koikatsu creators supposedly being in the exact same situation, so maybe there's hope?