I'd say that your evaluation of the interaction systems is spot on. If you open the script files (.gd files are plain text script files), you'll find that in some areas there is the potential for a bit more complexity than the player is made aware of (lube exists in sex) and in other areas there is a complete lack of functionality where the player would expect there to be something (tools like the blindfold). Both systems use almost completely generic characters, even for the talking animals, so everyone has basically the same personality and reactions. Most of the variation comes from RNG or poorly balanced and indicated stat differences.
You are not alone in wanting more from the interactions as they are quite monotonous, but adding significant variety quickly adds up to be considerable investments of time and creativity. This game ceased official development a couple years ago and only receives bugfixes(https://itch.io/t/1167355/bugfix-for-10d-v6b) when I find the time and energy. I don't mind including quality of life improvements from the rest of the community when I feel that they are appropriate, but my goal is to not significantly change the experience.
I suspect that most players simply stumble their way through the interactions as I haven't seen any detailed guides or chat. I opened up the scripts and compiled a chart of many of the actions for personal use (rarely shared on the Discord), though that is a bit outdated now. There are currently or have been a few mods that alter the interaction systems, though these are generally minor changes to include new actions. There was one mod that planned to tailor the meet interaction actions to the various traits, but I believe that was never finished. I have not seen any significant efforts to change the action transparency, though this is a issue with the game in general.