I think your feedback here is good, and I want to comment a bit on your first point. I think, setting aside the sexual content, lifesims share a basic structural problem with most 4X and grand strategy games, which is that they have real difficulty modelling internal instability and entropic tendencies within social systems or relations. Everything is way too stable once it's set up, which is what really allows you (in the strategy case) to snowball instead of actually having to actually work to keep what you've already achieved stabilized (you can even see this with adult games, e.g. in Free Cities. It's an inconvenience to set up your slave whore empire, but once it's set up, you're just swimming in the cash and that's that, the secondary gameplay loop is voided). In the lifesim case, relationships are entirely stable when set up, so the only point at which they may fail, is when you're trying to set them up. If the NPC has some compattible properties, or has randomly liked you because your charisma is high (or if you just grind interactions), you can start a relationship, and that's that. I think it's an understandable design decision, given that this sort of game is in the wish fulfilment business, but not a very good one, because of how it makes the game grindy. You also can't just introduce entropy through random events, because RNG is by definition arbitrary, and people don't want their relationships to end without any reason.
But I think relationships can be fleshed out through events rolled when your partner is in the same area as you (like the jealousy event) or when you're on a date. These should be based on existing and ideally also on secret negative properties, introducing reasons for the player to want to break up with someone if they decide they can't tolerate their behaviour or else something that they would need to manage if they want to stay with them. There should be an organic reason to move between relationships (as we have IRL). It's the only way to avoid the two extremes of fucking 100 people or being with just one. This would also flesh out the *actual relationship* from the initial dating stage and after it, since it would give you events while you are just being someone's partner.
Another related problem that I have mentioned before is that every NPC is currently equally (and fully) competent at sex. The sex mechanics need to be fleshed out further, and NPCs should a) not last equally long, b) not always be interested in getting you off, and c) be more sticky about what they want to do with you and what they don't want to do with you. Again, this is almost entirely what people IRL mean when they talk about being "sexually incompattible", and it's another organic reason to end a relationship, especially a non-romantic one. At the same time, how much sex you want to have should be soft capped. People don't just experience need and frustration, they also experience satiation (arousal fixed, you just don't want to have more sex), contentment and physical stuff like soreness. I feel this would give a non-moralistic, narrative reason for the player not to have sex all day every day / whenever someone asks (besides avoiding slut-shaming, which currently seems arbitrary anyway. A more robust reputation system would work there, e.g. not fucking on the first date, so that the rumour doesn't spread you're very easy, so that you don't get slutshaming events, or events where people try to take advantage of you without being interested in you --another aside here: CoT currently models, sex with people that like you, and sex with people that hate you. But the most common way people may feel bad is when they have sex with someone that is just getting off with them and does not like or respect them, or have any further interest in them. But such people don't necessarily dislike you, either!), add a lot of flavour if they choose to or need to (if you are a sex worker, for example, and you have to make money, and you choose to take that one more client even though you're a bit sore and tired already etc). Because none of these games that I have played reliably model these, the player never has narrative incentives to not be hypersexual in comical ways. This is bad because it makes the decision to be normal completely arbitrary, and also voids being slutty of its actual appeal as a phase or life path.
These would all also influence trying to juggle multiple relationships. If, for example, a particular NPC needs to see you at least twice a week, not doing that could result in them being less interested in you in the future, so it soft caps how you can pursue other stuff.
A last couple of things I would add here are: A) there should be ways for dates to really fail. It's wrong to ask the player if they enjoyed a date, instead of having the date fail or succeed for in-game reasons, including because of factors that the player has some way to manage during the date. Again, the way they are currently structured vacates them of both narrative meaning or gameplay interest. B) More people should ask you out, more often, especially if you're already dating. In order to allow the player to totally control gameflow, this relies almost entirely on you calling them up, but this is unrealistic and also makes progressing relationships cursory, since you never actually have to seriously manage your schedule to be able to satisfy people or fit dates in. This adds flavour and mechanical interest (e.g. I can't come then, I have a class, how about that time? Or maybe you want to skip class!). C) Related to point B) making you have all dates at 11 or after 6 is very unrealistic and hamstrings the gameplay. Especially for stuff like bootycalls, you should be able to ask someone to come over then and there (maybe you want to have sex in that empty block of time between 11 and 3 on tuesday, for instance), but in general, being able to pick precise times is important to organise game time more efficiently, and also to incorporate scheduling conflicts and such, and also to make it possible for you to stand someone up --or be stood up.
