Reading people/situations:
I'll ask the players to look over the Read questions before play, and to then roleplay toward the question(s) they want answered before rolling. "I chat and flirt with him for a bit. Okay. Roll. 11. Now, how can I get him to betray his family?" will be off the table. You've got to bring up his family in the roleplayed interaction.
Second, if my MC answer is, "To get him to betray them, you'd have to mind-control him," then they'll have to accept it.
Second part is dead on, but hold up on the first part there. The player can of course ask that! How? I size this guy, up and think to myself "Now, how can I get him to betray his family?"
BUT, your answer as MC also has to fit the fiction. So the PC is sizing this guy up and thinking how he might betray his family, so.. what do you say?
"Well, he look's like somebody who would break if you tortured him."
"This guy has multiple polaroids of his family. Know anybody else with polaroid pictures? No, of course not. Because there was only one polaroid camera, and this guy used it to take pictures of his family. He's the kind of guy who'd rather die than betray what he holds dear."
"The way he's eyefucking you every time you speak? He wouldn't piss in your mouth if your throat was on fire. Betray his family for you? Don't make me laugh."
All three answers based on what the PC did to do it. And they're all statements about what the PC sees, not what he thinks.
If the PC was looking through this NPC's papers and reads him, then you'd probably give a totally different answer, although the second one (polaroids) wouls also be appropriate. But if they find the NPC's secret accounts ledger, maybe threatening to reveal it would get him to betray his family? But you wouldn't give that answer to the guy reading by looking.
Rolling a 7+ lets you get to ask the question, and you get an honest answer. Doesn't mean you get an answer you like!