Wow, thanks for the detailed reply. And thanks a damn lot for the link! Should have guessed, a script by SumRndmDude, heh, they are popular. Just like Yanfly and Mog, they make good stuff, but I tend to stay away from external scripts to keep things as vanilla as possible for maximum compatibility. Still very good stuff and as far as I can tell from scripts I've looked at, they always check for cross-compatibility between scripts.
No worries about MZ, I have a license for MV (and for the other, older engines, as I don't use MV much) and might eventually consider getting the Steam one. MV still allows some compatibility between projects, though you apparently can't playtest them without some tweaks. No worries about health either, I'm just a zombie at this point, haha.
Glad to know some things already were in your workflow, I didn't want to make you change your mind and cause even more work! For sub/dom, if you fear missable scenes, I suppose you could just "level down" or things like that? It all depends on how you eventually want to use the current switches. Almost all developers implement quick and dirty things to "nerf" oneself (and store progress) so that it isn't lost, though I can't really think of a... "realistic" way for sub/dom storage. It's usually with XP, levels and gold, but variable storage can be pretty much anything.
For Penny's dialogue box (likely not the only one), I believe it's mostly a message issue where it goes transparent instead of the default window mode and also drops the face. That's the main issue with all RM engines - message creation interface limitations really causes wonky stuff when you have a lot of dialogue and you can easily make mistakes for a few of them. Text search is also hellish unless you use plugins or directly search the json code in all files to make sure you catch them all (hello headaches, especially with regular expressions).
As for the sprite, thought so. Really should share one of the "safer" character sets so you can see if this helps you find a way to edit the default charset file to your liking (by rearranging the directions). And damn, I missed the rent one, nice catch... I'll admit I didn't test that too much. (Being able to refuse to pay rent even when you're filthy rich just to get sent to jail is a nice touch too!)
No worries about the random suggestions, please keep doing whatever works best for you, that's the point of developing a game. If you're unsure, just wait for additional community feedback, you can't please everyone and you shouldn't let us lead you astray. (Yes, Elizabeth's totally unexpected climax worked like a charm here, and it may cause others to freak out or just laugh, fetishes are hit or miss, not sure if it's the same for dialogue. I'm sure Aerodynamics was happy to find out Lost Treasures caused many non-fart fetishists to laugh the hell out at the game because it's cute and funny - and some of them unexpectedly grew the fetish out of nowhere.)
And this is where I stop the long post and take the moment to appreciate this one part...Not only did you acknowledge to it but you also know why it's dangerous and know how to solve it before it becomes a problem. Developers (and writers) with this mindset are getting scarce. It's a good thing to see some, and the thing is, you even admitted to being mostly a writer. What if I told you a certain self-proclaimed master developer and dialogue writer could learn a thing or two from you?
Please keep it up! That's the spirit.
Either way, please make sure you give RL (and your job!) top priority, it's great that you are able to multitask, but that shouldn't distract you! As long as it's a break for you, that's all good, I guess.
(If you need help with proofreading the dialogues or minimizing the code, feel free to ask around. It'll likely take way more than one user but I'm sure people who love your game will be happy to assist you. Just gotta find out how to extract massive amounts of JSON and reinsert them, there has to be a less painful way. I'll look up on the official RPG Maker forums, text strings aren't really a problem but minimizing the code can be unless they also have an exhaustive list of status codes for corresponding RMMV/RMMZ functions. JSON format makes it easier, which if I'm not mistaken is something added since MV. VX and older had proprietary formats such as rvdata for game data structure, so it was quite troublesome. Now even end-users can actually mod commercial projects for their own use without fear of violating reverse engineering laws, though a good bunch of countries still allow reverse engineering for personal use, but that's a different story for another day...)