The real-world stuff is intentionally pretty linear for now and at least to 1.0. There are 2 endings planned for 1.0, Corrupted (all mental changes done) and Happy ending (not all mental changes done by the end of the Roya storyline).
There is lewd stuff in the real-world, several scenes so far, it just takes a while to start happening, something like 80% of the current content.
The dev has opted to go deep rather than wide with the corruption, and wanted to tell a story (real-world and Roya) as well as making a full JRPG (Roya). This wouldn't be possible with a lot of player customization right now, or it would extend the way to 1.0 by years.