regarding the answer to question 1 (otherwise good): How (actually where) do I create the creature? I can't put in coordinates, because there are different area possibilities.
Paint. Photoshop. Whatever you like. You also willIETME. If you open the relevant area file (from a house, for example) and remove all the NPCs, Triggers and Containers etc from it, and renamed it, then you would have a new area based on an existing one (Bioware had some blueprint areas for housing).
And once I have my area, how would I put it into the game?
Seems silly to me. In addition, those stats are befitting of characters who rolled a dozen times and took advantage of the ability to move scores around. Definately broken for an NPC.