The "Fight the demon" quest was already fix-patched 2 or 3 days ago, we. So if you download it there's some small fixes. (We'll bring an updated version very soon for some bugs that older PCs have with some animations)
The Diamond Scene isn't unlocked yet since the other succubi are missing some more scenes, we'll probably throw a hint there that it's in development - you're right.
Footjob isn't in the game yet, not crossed of in our fetish list.
Milf is currently Thalia, Diamond probably also as soon as she gets her scene