I have limited options to test everything, but I added this to 1.18

Pictures: the base download only includes a couple of placeholder images. To get girls looking like the screenshots you need to install image/character packs into the game's resource folders.
New packs are here: https://airtable.com/apptYzyWwRURix9tK/shrGkJwppxCUVe41U
Colored names: you've actually spotted two separate systems. In the item shop, row color is the item's rarity/price tier, so your read there is correct. For girls, color is not rarity: gold means a unique hand-authored girl from an installed pack, plain blue means a randomly generated one. Red rows (when you see them) mean "this girl needs attention," e.g. low health. Unifying the systems is planned in the future
Glad you found the cures. A few things that'll make the disease loop much less painful:
You don't have to apply cures by hand.As long as you keep cure potions in your brothel's item stash, the game auto-treats any infected girl at the end of each turn (this is on by default, it's the "automatically use items" setting). So the move is to buy a few cures whenever the shop has them and just sit on the stockpile. The Elixir of Ultimate Regeneration is the best one to hoard, since it cures all the STDs (and clears up scars and other afflictions too), rather than the single-disease cures.
Hire a Matron. A Matron pulls diseased girls off duty and warns you in the turn summary, so you catch infections instead of finding out the hard way. Without one, a sick girl will keep working (and keep spreading it).
There was a bug where girls could catch STDs out of nowhere, even from a clean player with no interactions. That's fixed in the upcoming 1.15 release.
Yep, the up arrow on each girl's profile bumps her housing level, which keeps her happier and better rested. The mechanism will be redone in the future
CobaltStrike? It doesn't flag it as malware - it flags it as matching patterns found in malicious software because of the automatically detected behaviors. It's a heuristic test. Real reasons I don't know but it's likely any or all: it's a new executable without history and it has many behaviors which could be malicious: dynamically linked DLLs (ffmpeg for videos, webp libraries), opens links (mega download for the updater) etc. You can mark it as not malware and eventually as the popularity grows, Google will stop.
Also in upcoming 1.12 I added manifests which should stop triggering UAC.