I am using this setup for my home watering system. the smartApp has a lot of logic for timing and scheduling. Maybe by commenting out some lines will simplify the ST to a simply 8+ relay switch. you may still have to make virtual switches to control individual relays from other smart apps.
I just started playing with The Smart Room Controller (formerly SmartKitchen). @dome has developed a great starting point for both a light and relay project I am looking to do. you may be able to see what he coded and use the switch part of his setup.