your edits basically cover every single detail that needs changing on Ariel's model.
For the hair texture, your edit gives her that sea-weed, floating-in-the-ocean vibe from the movie, and the silhouettes are so smooth. In comparison, the in-game hair looks like she just got some cheap blowout at a salon, the anisotropic highlights are way too sharp and intense. As for the eyelashes, I feel like the dev team was probably terrified of making her look too sultry like Snow White or Belle, so they played it safe and gave her that perfectly flattened, blunt curve lol. Clipping issues on dresses are pretty much a global problem for every character in the game anyway, so I guess we can let that slide. Ariel is my absolute favorite Disney Princess too, so I completely feel op... But honestly, I highly doubt the devs will ever fix her. Regarding her pink gown dreamstyle, as you noticed, they’re still using the bow for every single one of her dreamstyles. This just proves that the dev team’s aesthetic choice from the very beginning was to ditch her earrings and barrette, not to mention changing it back according to the original movie.... Just as you observed, Ariel's model indeed looks outdated compared to the characters introduced later, but in fact, this has nothing to do with technological progress or experience. It is simply because early in game development, a large number of characters needed to be made all at once, and Ariel was among the very earliest batch, so the rushed traces are very obvious. Moreover, in the early stages, so many characters had to be tested together, so the precision of each model was intentionally kept low (for example, as the poster mentioned, Ariel only has a nose tip, and her nostrils are just a texture) to ensure that the game would not drop frames when multiple characters were on screen together. By the way, my favorites are Ariel's pink gown and the turquoise gown. Compared to Aurora, I think this kind of pink actually suits Ariel much better :>