Preview window: as large as possible for your monitor size. Not so big that you cant move it, but as big as you can get it.

Render size: depends on the image, but I always do mine at 2000 pixels on the shortest dimension.

Building to scale: start with a character so you have a measure. Load in the building, with the door near your character. Scale everything up and down so the door height is comfortable.

Best render settings: again, it depends on your image. I use the default Firefly with ambient occlusion for all lights, but that;'s just my preference.

Putting your large runtime on another drive wont solve the problem. Set up a second RT and put that on the external, but keep your main RT with the application and keep it lean. I set up an RT for every new series of images, so I can archive it with the finals and then take it out of commission so it doesnt slow down my Poser.

Dressing the doll and saving it: yes, you can do this. Build your character and all her stuff. Click on the body, then hit the + sign in the figure library. Poser will ask if you want to save just the figure or the entire group. Tell it the group.

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