If I may interrupt, the "talk" option is used in Shining Force III a couple of times. The first time you use it to talk to Hayward in the second battle and then he joins your squad, and the second time is in Scenario II where you use it to dissipate a fight, proving battles are not always won with swords

In SFIII the icon replaces the hold/search button at the relevant moment, rather than happening automatically
The interactive option is a bad idea because it could mean they'd say the wrong thing and the person wouldn't join/event wouldn't happen, presuming that's the kind of event you're looking at following interactive dialogue.
That's just about all I have to say about that. Carry on
