Hi Ritzknot,
Thanks for the interest, we really appreciate it. We're always happy to see other omegaverse fans as we are also huge fans of the genre :)
We don't have a time estimate. I've just posted a comprehensive development status which you can see here. You might need to wait for the finished game as we work on it slowly.
There is a sexual assault scene/sexual harassment, but the actual rape is only hinted offscreen in a bad ending. We don't show explicit images of genitalia and such. Mannequin is a plot-heavy game, but there is a fair number of erotic scenes.
Let us know if you have any other questions and have a great day <3