Returned to Level class. I have switched between big classes and browsed through them, fixing everything in sight. Level class is possibly the worst of them, because the dungeon generator still has some problems. It can't generate all level themes yet, but I'm working on it.
In some parts I have made a decision to settle for less great stuff to speed up development. Maybe I'm really looking forward to create a playable version, no matter what features it could be missing. Still, I'm pretty sure that the first playable version is not going to be a release version.