• How's your night been?
  
• * play it cool
  ^ may need a green (or blue?) Feelgrid, but this choice doesn't seem to matter much
  
• I get it
  
• Maybe I'm mistaken
  
• Axes are way too messy
  
• Can I just ask you some questions?
  
• That would be a useful superpower
  
• * need to know how exactly they know each other
  
• Savy worked at Capra!?
  
• I definitely did not
  
• Did it seem like she liked working there?
  
• * find out when he'd seen her last
  
• What were they arguing about?
  
• I do know her
  
• Why would she do that?
  
• What would they do?
  
• * too risky to say much more

Result:
This seems just about the best possible first convo with Charlie. He's relaxed almost the entire time until right before you drop him off. But then he abruptly gets upset and still gives you just 1 star. More stars don't appear to be possible here. Charlie also still calls you the worst driver ever, but he does give you a tip, lol.

Achievement note: Doing this conversation as described above (or at least part of it) is one of the requirements for the Text Me Back achievement. If you upset Charlie and he shuts up early, you might not learn much about Capra, therefore Savy might not feel she has reason to ask you to be careful.

The first conversation with Luke is often described as a "guaranteed one star rating". But you know how they say the customer is always right? Just swallow your pride, play along with whatever Luke is doing, apologize for any inconvenience, clean up the mess, and move on.

Result:
Five stars and a big tip. "Uneventful."

Is it worth it though? Up to you, I suppose...

• sounds like a spa
  
• sorry, haven't updated my programming (limited; centered)
  
• * sounded like she knew what she was talking about
  
• * whispered eeny, meeny, miny
  
• lose a tail?
  
• genius safe-cracker
  
• hippopotamus
  
• * stayed quiet
  
• I like to think life itself is a gamble
  
• And going down Flambeur can make it right?
  
• Uncertainty? Of course.
  
• Can there be two Linas?
  
• * told what happened with Savy
  
• Wouldn't you be confused?
  
• * Taking in a burlesque show in Luz Rouge
  
• That'll be a more expensive ride
  
• What's this all about?
  
• * I thought I should tell her
  
• A witch?

Result:
Oona will tell Lina about Stanzmaschine. She will also give Lina extra cash, and a tip.

Alternatively:

• Refuse to talk about Savy, OR:
  
• Tell Oona about Savy and Luz Rouge, but then refuse to drive her there.

Result:
Lina will throw Oona out of the cab. Oona will be very unhappy about that and reward Lina with a one star rating. (I'm not sure why though—this event should be unexpected enough to yield some pretty decent entropy!) Lina will still learn about Stanzmaschine, because it just so happens that Oona gets out right in front of it.

• the quantum thing?
  
• ballon drop (limited)
  
• lottery tickets
  
• * didn't say anything
  
• annoyance
  
• it's just that you're kinda ... strange. no offense?
  
• it's easier to be strange when you've got money (limited; red works)
  
• that is not me
  
• eject
  
• what do you actually do?
  
• that's it?
  
• world peace
  
• weird job
  
• I do
  
• why aren't i her, and vice-versa?
  
• * quantum riches
  
• not going to learn how to be a witch
  
• ...
  
• halfway to Vegas
  
• * felt it, too
  
• do you really feel this way all the time?
  
• peace?
  
• * wished us all luck

Result:
Five stars, but still no tip ... unusual for Oona? Although you may have a chance at getting that bonus from her if you didn't get it in the first conversation.

• * awkward
  
• She does!
  
• Never a dull moment
  
• What's that sound?
  
• That's awful
  
• What happened to all that cookie talk?
  
• * eyes on the road
  
• * needed to know, but didn't want to wake Sleeping Beauty
  
• * play along
  
• Why would I help you to do it again? / This better not just be a 50/50 split.
  ^ choice doesn't seem to matter
  
• * do the world some good
  
• Depends
  
• * twist the knife
  
• 360
  
• * laugh
  
• What's the money for?
  
• * flip the locks

Result:
Sam offers Lina ¢120. However, no matter whether you ask for more or accept the ¢120, you actually get zero. The maximum you're actually able to get seems to be ¢90 (which is obtainable by neither protecting Luke nor helping Sam, and later asking for half).
This appears to be a bug in the game.

There's not a complete walkthrough here, because the conversation varies and a lot of the dialog choices don't matter much in the end. But these seem to be the ones that do matter:

• Nothing to do with being meek
  
• Trying to guilt me
  
• Not going to re-hash old fights
  
• I never said I was perfect
  
• You think I'm phony?
  
• So please, just stop before we go too far.

There are three possible outcomes of this fight with Savy:
• Lina can end up feeling blue (anger will turn into despair); in this state, Lina will lack the energy to fight Savy further, which Savy will take advantage of and always force Lina to go together.
  • Or Lina can end up feeling yellow, having seen through Savy's power play and being energized by it; in this state, Savy will realize that there's no point fighting Lina further and she will be forced to give in, with Lina always leaving alone.
  • Or Lina can end up feeling green, having understood Savy's play but keeping a cool head about it. This is the only state in which the player actually gets to make a choice for whether or not Savy should accompany Lina. Savy will defer to whatever decision you make. The choices listed above should lead to this outcome (some others do as well).

This last outcome is particularly useful because the game will add an extra save point after the fight, which makes re-playing the endings and the epilogues much easier.

Epilogues may unlock based on Lina's previous conversations. Epilogues are known to be possible with:

• Carlos
  
• Fiona
  
• Gideon
  
• Liam
  
• Oona
  
• Savy

The epilogues differ depending on what you did with your Feelgrid.

I may or may not add new conversations to this guide if/when I replay the game.

If you want to add conversations to this guide, let me know in the comments! I'd be happy to give you edit access.