15, 24, 30 for the Tav asks?
15. What motivates your Tav to either embrace or resist the tadpole?
She...well, she never quite embraces it, but she does lean into its power at first! While the idea of having a leech in her brain is horrifying, and she's deathly afraid of the pain of ceremorphosis, she's also extremely used to a narrow view of her own survival. She hasn't looked more than a day or two down the road in over a decade, so it's very much a "if this helps me survive this moment right now, I'll do it happily and deal with the fallout later" thing. She's also half-convinced the prism will fail and the worm will take her any moment regardless, so why not snatch up what she can get? She's going to die any moment anyway; might as well go out knowing she did everything she could to stay alive beforehand.
However, after Myrkul & the early stuff in Act 3, she suddenly starts wondering if they might be able to get rid of these things after all. If she might actually have some kind of future possible after the Absolute and Cazador and everything else. If that's really on the table, she wants to be present for it and not a dribbling husk, so she stops feeding the parasite. She does use what she's got, though, and post-game she does faintly miss exploding people with her mind.
24. What first impression does your Tav give off to strangers?
When she's just been orphaned, she's one of those big dewy-eyed tearful kids they use in those horrible fundraising Sarah McLachlan ads. That doesn't last long, however, as she learns how to avoid being noticed in the first place. If she's actually seen, she's usually just looking hunted and desperate as she tries to extricate herself.
Post-game, once she's become better at interacting with speech and honesty and open exchange of ideas rather than petty theft, I think she's much more comfortable being seen in day-to-day life and going to social events where part of the goal is to be perceived. As she and Astarion travel around the continent, I think they play games like "let's pretend to be minor royalty in this new city and see how many balls we can get invited to before they throw us out."
She was brought up well before her parents died, so she's not going to make major crass faux-pas; instead, she's friendly and conversational, but she always has a touch of distance in her eyes. An invisible wall, a little - disdain isn't quite the right word, but a little - impersonal arrogance, maybe. She's with you, but she's not one of you - she's seen things you can't dream of, and she doesn't really mind if you feel it. I think it's more pronounced the more expensive the society is, for whatever that's worth. She certainly feels more at home in the gutter, even if she'd die before going back there again.
30. What are your Tav’s intentions/goals after the end of the game?
Get Astarion his ring, first and foremost. Once that's settled, they travel everywhere they can get passage. They've both been trapped in Baldur's Gate for so long, even if their raw years are disparately dispensed, and she wants to see everything the world's been hiding from her! The Underdark, the City of Splendors, Calimshan deserts, the Moonshae Isles, Evermeet, Marsember (the City of Spices! it sounds so beautiful until they get there and it's all misty swamp and haunted bogs), Cormyr - beaches! (which they both hate because it's TOO SUNNY and TOO SANDY) - basically anywhere they can get a portal or a road to. They're not hoofing through the woods anymore if they can help it.
I do think Tav splits the money among the companions left behind (so no shares to Wyll, Karlach, or Lae'zel directly, though she takes out some accounts at the Counting House for them and starts accruing interest in their names), and she uses her connections with the Counting House & the Thieves' Guild to start building some portfolios of her own. She never wants to be in a place where she has to think about money ever again. (I think she carries letters back and forth from Wyll to his dad, & Wyll gets his dad to get her in touch with one of the city's trustworthy financiers to help her get all this started.)
Between all that they visit Lae'zel in the Astral Sea for like a week, and when they come back both of them are like, "WELL that was fun let's never do THAT again," but they do visit Karlach and Wyll in Avernus quite often! I think they bully Helsik into opening the portal for them the first several times, but they don't like being dependent on her or the location, so they steal a very hefty supply of the rare materials (esp. the infernal marble) and a copy of the exact rites, along with contact info for more supplies in future, and they repurpose one of the portals in the House of Hope to open to Gale's tower in Waterdeep. (I don't think they tell him ahead of time.)
At some point they figure out how to extend Tav's life, but that's way down the road. Also I think she starts a Thieves' Guild with the tiefling kids that's secretly an orphanage/pipeline into gainful employment.
