I don't understand infinite re-roll?! In essence you are saying you want to succeed any check you make in conversations? Or Just in gerneral? Why? Why is "failure" such a bad thing? There are usually other methods of getting round said failure (unless a fight ensues) and trying again later (like with character conversations).
But ok, let's say that's your point of view and all views are equal, then I don't think infinite re-roll is the way forward UNLESS you want to be able to select when you fail and when you don't, in which case in an easy option or optional selection box, yeah, you could add infinite re-roll points, I forget their name, the ones you can earn. Otherwise infinite re-roll is a waste of animation time, you could just remove the die and have auto-succeed.
I personally would rather more nuances to "failure", I want to charm Shadowheart but she rebuffs me now, but later on I do something heroic or evil that opens her eyes and she initiates a conversation recognising that she was wrong before. Black & White Suceed / Failure sucks. Sometimes it has to happen, I mean if you fail a last ditch intimidation roll and a fight ensues and someone dies, then that's that.