At the last meeting of the nerfing committeee, the GMs agreed that we're not all on the same page with the conversation-type skills (and, in fact, the GMs haven't been on the same page as each other), so here is an attempt to clarify and expand what some of the various talky skills do.
Fast Talk and Persuasion are both for convincing someone else to do or believe the thing you want them to. Fast Talk is fast, often short-term, more easily usable with things you don't believe yourself or implausible things, and is more likely to have them realize later "Wait, what did I do?". Persuasion is more for a longer-term shift of opinion, takes a while to perform, and is more easily combined with things like logic.
Conversation is, at its heart, a two-way interaction. You can't converse at someone, and you can't have a conversation in which you aren't interested in listening to what the other person has to say.
Conversation includes "using conversation to learn someone else's views" (which we call Conversational Interrogation), and also "using conversation to try to sway someone else's views" (which we are now calling Conversational Persuasion). Note that if you are using Conversational Interrogation, you are asking them questions, but they are likely to be asking you questions. If you're talking to them about what you think about politics, they're talking to you about the same thing. (We often run this by having Actual Dialogue.)
You can use Persuasion in a one-way fashion (for example, giving a speech); you cannot use Conversational Persuasion that way.
Interrogation is a one-way form of asking someone questions, but it's an unfriendly one. There isn't a way to sociably find out things from someone in a friendly one-way fashion, without setting up a specific situation for it (such as a job interview), but both Conversation and Conversational Dodge can be used to try to avoid giving too much away. (Strong Willed can be used to avoid answering questions when someone else is using Conversational Interrogation on you, but it's not going to work so well when you're asking questions.)
Gather Information is for finding what "people in general" (in a particular area, or a particular group) know or think; it's not for convincing a particular person to tell you their secrets.
Conversation is being increased to 5 points, and can be used for all of Conversational Persuasion, Conversational Interrogation, and Conversational Dodge, which are 3 points each.
We have not been consistently playing things as described above, but we will attempt to in the future. If this is greatly out of whack with what people think they wanted when they bought their skills, or you can't afford the increased price for Conversation, we're allowing adjustment to the skills shown below.
Skill costs: ------------- Persuasion 4 Fast Talk 4 Conversation 5 Conversational Interrogation 3 Conversational Persuasion 3 Conversational Dodge 3 Interrogation 3 Gather Information 4