Honestly, that's one of the main issues I saw with this system right out the gate: Rolls seems to be a very black and white decision. Either you succeed or you fail and then the results listed are carried out without question. It's like when people say a nat20 in D&D gives you an auto-success in whatever you're doing; sometimes, it just doesn't seem like it should work that way.

It's kinda like if I had a character that tried to convince a good and kind character similar to Stargaze to turn against their friends who've done nothing to wrong them and rolled a 12. Sometimes, it just doesn't make sense to let that work, no matter what is offered.

Plus, the way the system is structured, failing only gives you experience, so is there a reason to not just try again and again? It feels like the incentive is to just spam rolls left and right whenever possible, and feels kind of abusable to me...?

However, in this specific instance, I do think you might already have your answer to the questions. 

Perhaps Skobeloff gleams exactly that: There is absolutely nothing Garrock wants to do less than talk with his family. And that there's probably nothing he can do to convince him right now. And that would probably prompt us to find a way to try a roleplay angle to help this problem later, rather than figuring out how to resolve it right this second.

So "How could I get you to talk to Rudrick (and hopefully by extension to Sunglow)?" - He would come to understand that nothing they say or do in this instance will successfully get him to do anything with his family.

That's just my thought on the matter anyway. xD