Floor 6: Will be fixed.
Floor 7: You probably mean Floor 9, the zombie island. Try talking with a fixer in a church before speaking with her again. Voodoo shrine will be fixed.
Floor 8: You probably mean Floor 10, the thousand snake castle. Yes you can. (hint: the boss is actually south)
Theodoxa hasn't been released yet. It will be the biggest update yet, I have been building the city for 2 months now. For now you can reach the forests outside of it (Floor 13)