Eric, this is an interesting idea and it has been discussed before. Your biggest challenge is to design an interface to that would allow you to select a floor plan and add “devices” to arbitrary places on that image. Communication with SmartThings is not a problem, as such.
From my personal experience, placing device icons in literal floorpan “rooms” will quickly clutter the user interface, especially when using devices with more controls, such as thermostats, for example.
This would be a fun and challenging project, although might feel overwhelming if you are just starting with web development and JQuery. If you have particular questions, please let me know. Been there, done that…