Sometimes when the iris is light-colored, you cannot see the color or shade of it well against an outer white background of the eye. A thin iris-to-sclera border could solve it.

Military themed uniforms, decorations, things of that variety, to give the option for a military testing vibe?

Pubic hair and under arms hair

You know how in the original game you were a disembodied prescence that just acted as a pair of hands? Well I'd like to see that again. Added as an extra mode, your characted is a sexless, ageless specieless sombody in a sealed hazmat suit. You can only use your hands and whatever tools you have access to and nobody you experiment on reacts to you as if you were a specific person.

This is for people who would like a slightly more proffessional working enviroment, or just want to focus on the person in the rack without anyone else taking up the spotlight.

A bit of a disclaimer: what follows is an extremely resource-taxing suggestion. I would be perfectly fine with the outcome if it was rejected outright or if its consideration was postponed until after the optimization stagedue to technical limitations and the sheer amount of coding involved. However, in my humble opinion, it would be extremely cool to see this in the final version of the game, even if it was part of a post-release update.

Ability to create flaming characters, with the ability to fine-tune the flames individually for each allowed body part in terms of its intensity, color, temperature and sensitivity of all of the parameters above to arousal and stimulation levels. Possibly, with an extremely nerfed fire breath.

Adding additional dialogue for reaction to the fact the character is about to either fuck somebody as or be fucked by a living walking torch. Setting default interactions as temperature play adjacent if the used body part had been customized in this fashion and its temperature is sufficiently high or low. In a nutshell, integrating the system fairly smoothly by adjusting relevant behavioir patterns.

As I said, this is a really daunting challenge for the dev to code and implement this feature. Maybe it is even more of a challenge for whatever rig may run the game to not go up in flames immediately after a character enveloped in flames is shown. But a man can dream, right?

Because making a full-fledged demon or a somewhat functional dragon would be rad as hell. 

P. S. Recasting all of this for icy mist and cold breath would be amazing too.

I just want to see a enormous monster cock destroy little men's asses

Currently, drugs apply their effects when administered.

I'd like to suggest the ability to make drugs that are persistent and/or have effects based on other triggers. The most obvious example would be a drug that after taken, would apply some effect (ex. grow X%) each time a subject orgasms.

Players could even use this to setup chains with multiple drugs, or even complete/repeating cycles.

Would love to see some clothing accessories like leather cuffs you can wear on ankles and wrists. :D

Currently, you're stuck choosing default patterns and decals for your characters.
While custom patterns/decals are probably going to be in the final game, I have a related idea.

In an editor similar to the decal adder, you could 'paint' a color onto your character, with various brush and erase tools. The result would be a custom layer, fine-tuned to your character settings.