All buildings are different sizes so it is difficult to judge. The door size is the best guide but even that is not always right. Stations sometimes had enormous doors. My dad had an N gauge layout with a Superquick OO terminus station. It looked perfect.
I reckon it is just a case of using eBay to sell their stock. Instead of shopping around on line eBay is much easier with several retailers all in the same place. Looking at different web sites is fine if you have the time.
I think a base on figures looks awful. Just make sure the bottoms of the feet are nice and flat then glue or pin them on to the board. This is how I do it. /media/tinymce_upload/9ff44af7917974363c20dc9815d73220.jpg