I know it, but there is something wrong with my sandmill house. I can fly though the walls and roof.
Torque constructor has those prefabs there for anyone to use,there is nothing saying do not use these,so as long as people are not saying they made it i have no problem with there use,and as for finding new textures,torque has about a dozen that come with it that are fine,people here do not realize that textures are sold,yes there are free ones but for a good decent one you have 2 choices,buy one or make your own.
as for you can pass though the walls you might have a collision,click collision and then click detail,also how are you saving your difs? i save mine as legacys and test them right after i make them,i had big problems with pass though walls and seemed to have fixed that problem.
as for removing the structures i would not,any fool can make a map with no buildings or structures,we need more maps like vice city and san anderas