Making something like Naked Ambition: Gold instead of Clothed Ambition has two problems with it. One, I don't know how much money I can actually make selling NSFW games upfront. Look, the biggest forum for these products is literally a piracy site. That doesn't give me confidence in high profit margins. I don't make all that much money off them now, but it's hard to profit off giving away stuff for free so I'm not complaining. I'm making another game right now that I'm going to sell for around $10 straight up. If that does well financially, making Naked Ambition: Gold could make sense. Two, Clothed Ambition would have a new, bigger market. How many people would actually pay money for Naked Ambition: Gold over just playing the free version?
Making a whole new game would take way more time and way more money. The reason to make Clothed Ambition in the first place would be to use all the art and writing and design I've already spent 1-2 years on and use that to make another product for better return on investment. Making a whole new Princess Trainer inspired game would be just that, making a whole new game. I don't gain anything from all the work I've done on Naked Ambition except experience and perspective. And while that is valuable I would rather just make something else at that point.
I can't speak much on the subject of money being made by selling your game, especially since I don't know your conditions and what you would consider acceptable when it comes to sales, but what I can't see is how it would hurt. I gave Steam as an example since I see quite a few NSFW games on there, but I don't know how their service works on the developer's end. I assume they take a certain percentage of the amount the game is sold at with perhaps a certain flat minimum, but games are sold at very low prices all the time, and since there are also so many low-effort games of all kinds on Steam I also assume they don't take much else, like a fee for the game simply being on the platform. So, unless I am very wrong about this, having your game on Steam seems like it could only help, even with "marketing" to some extent since it would be displayed for those searching for NSFW games. It has millions of users, some are bound to find this game interesting, of that I am sure.
As to how many would pay for NA:G over NA, I also can't say. Hypothetically, if you were to have NA:G as a paid version and NA as a free one, it would depend on the amount of content NA:G has over NA. I don't know how much more you are/would be willing to invest into this game, but if you implement the ideas from the Clothed version, then who wouldn't want to play the version with more events and replayability?
About making a new game, it would indeed be a very large investment, and I only suggested it with the assumption that you would make it after finishing your plans for NA. You mentioned the larger audience for a SFW game, and that would also, in my opinion, work better with a new game. My reasoning behind this is that if you reuse the assets from the NSFW version, it would be easier to associate the SFW version with the NSFW one, perhaps creating confusion, and you mentioned not liking the idea of having PG-13 stuff with NSFW stuff under one label. Of course, it would all depend on just what your intentions are with the SFW version, your ambitions with the current one and so on. In addition, as a purely SFW game, it would depend a lot more on the gameplay and story/characters, and as you mentioned before, stuff will need to be rewritten. Because of that, I assumed that you might be interested in simply telling another story instead, not necessarily completely different but clearly not the same also. Something like FMA and FMA:B. And at that point, perhaps the current artwork wouldn't work.
A solution might be to just alter the assets that you have in such a way that it would not be apparent that the two versions are "related", but I'm not sure how feasible that would be. Of course, this is only if you consider reusing the artwork as being a problem.
A mention that I might make however, since I keep mentioning Steam so much, is that users have to choose to see NSFW stuff, so you shouldn't worry about being in trouble as people should know what they're getting into, if that is what worries you when it comes to having stuff under the same label.
Anyway, the overall thing that I'm trying to say here is that there is a market for NSFW games, and while it is smaller than the SFW one, the things on offer are also in smaller quantities. So you wouldn't have as many customers, but they would be more likely to be interested. So if the main reason behind wanting to make CA is the larger market and money, I think a better solution would be making NA even better and selling it, assuming you are interested in doing that. In my NSFW biased eyes NA:G would work way better than CA. I suppose there is also the fact that CA would have competitors such as LLTQ, where NA:G would be it's own thing exactly because of the NSFW elements.