Does anyone know how to get on an NPC's good side? I've run into numerous NPCs and I'm sure some of them have maps that I need. I can't seem to charm/bribe/peace etc them enough to be able to trade with them (except for the ones I've helped out, like Boerigard). Any interaction, whether with spells or money or just negotiations, ends up with them getting angry and leaving.

If you're playing Wiz Gold diplomacy is broken.
If playing Wiz 7 a character with Diplomacy skill helps.

Is killing them the only option then? And the gog.com version of the game doesn't say 7 or Gold, it's says: Wizardry 7 Gold. I don't see a pure 7 version anywhere in the files I've downloaded.

PetrusOctavianus was referring to the Wiz 7 DOS. Check under bonus content.