1) Hair/Fur Patterns based on existing skin markings
2) Frog Girl/Kerokoras penetrative win scene - I'm not really into footjobs, and I just find it weird that the only way to screw these enemies is to submit to them - really makes winning feel unrewarding, especially since early on, you're unlikely to be ready to go right when you encounter them. Simply added a dick fuck win scene would be great.
3) Aliss' Exhibitionism Xpac - Pretty sure this has been explicitly hinted at as future content in-game for a few years now, but I'm not sure if it was ever really in the works, or was just a suggestion to other authors as a potential route it could go. Either way, I'd love to see what antics Steele and Aliss could get up to together.
4) The Return of Hand So - I'm trying really hard to remember if there's anything you can use Hand So's data bead for? I'd love to see some pay-off for that questline, since I'm not really sure where they were going with it (insofar as giving you the option to save what otherwise seemed hellbent on destroying all organic life) or what it's planned to be used for.
5) More Omega Fever Scenes - I just really like this perk, and want more scenes to go along with it. There's already a scene with Syri, and I saw someone making one for Milodons on Uveto. I could easily see Liriel having fun with a Steele that's overwhelmed by buttlust, too. New Texas seems like it'd be a great place for a scene, too - maybe an anal-only Barn scene or whatever? Maybe Sera could take advantage of your Fuck Fever to make good on that promise to have you service her customers? Just a thought I'd throw out some ideas into the aether, since I really love the potential of this effect...also I love buttsex...
I also remember really wanting a tattoo parlor, and I recall one was being worked on way back that was shelved after its creator left...but at this point, unless there was a really interesting character associated with it, most of the mechanics have been moved elsewhere. Only things left that I really want in that vein are Nipple Chains and more event-based tattoos like Slut Stamp - maybe a belly tattoo that increases fertility and pregnancy speed? Or a body tattoo that you get from a gang that adds a small bonus to Physique, and a bonus psionic-based tease damage to enemies with vaginas (or just enemies in general, I guess would be better). Maybe even adding a tease option like with Myr Venom?
I'm just thinking aloud, but generally, I just think there's a lot more that could be done that I don't really feel like a tattoo parlor is necessary anymore. Not unless it brings something unique, or is a late-game option that allows you to obtain certain event-based status effects that you missed, as well as remove certain ones that you no longer want.
Aside from that: Ship Combat, Syri Recruitment Quest, Additional options for The Treatment, and Psionics/Cybernetics - these are already planned to happen at some point, so I just gotta be patient there. I also really want some penis decorations/cock-socks, but someone's already working on that, and I like what I see.