There are several perks that give more dialog options. I don't remember all of them off the top of my head, but it says in the description if it gives more dialog options. I believe there is at least one in every perk category (force, secrets, etc.)
Not sure if it is possible to get them all. Probably depends on if you get enough Influence points to spend.
Ah, okay.
I think the last perk I got was the one where you get a bonus (randomly) each time you gather plants.
Also, what perks are you guys' getting?