There will be no NPC's , rather, you can create up to six party members to travel through the game.
The romances in BG2 occur after having a party member in your party for a time. just rememeber when you reply to any questions they ask you, not to tell them to shut up or anything just plain rude.....well, except for maybe Viconia, but still, don't get carried away.
Also, only Viconia, Jaheira, and Arie can be romanced by a male, and Anomen by a female. It is also race specifice, I think you have to be human or half elf. Not sure about elf, but you can't have a romance as say a dwarf.
