Yes, it depends on how close you are to them. It's possible to get Thianne as an option, but she's more difficult to get close to than Vynn and Az'Lean for example.
I'm guessing you'd have to choose to hang out with Lester during one of the moments you're given an option to if you want to get enough points with him. As for getting the others, I'm just nice to everyone. Some might say I'm too nice (and in fact Az'Lean did say I'm too nice when setting up the barriers).