try playing around with the F5-F6 keys to resize the window the way you want, although I wonder if I shouldn't just allow again people to Alt + Shift instead.
The succubus brothel is in the military outpost (the area which "blocks" the north road uniting east and west Caliross). You need a merchant pass to enter the area. If you need more details on where it's hidden, check the "Military Outpost" section in the walkthrough.
Ginnuk is an orc you can meet during a quest for the mage guild. He got some more scenes if he wins over you, so you can't see the new scenes if you already finished the quest.