Can I use the BL600 in interactive mode (with AT commands) to connect with other Bluetooth Low Energy devices?

No, the interactive mode is mainly used for file management. For the BL600 to interact with other Bluetooth Low Energy (BLE) devices, there must be a smartBASIC program running on the BL600.

smartBASIC is an event-driven programming language that enables standalone operation of the module whereby sensors can be attached via any of the interfaces without the need for an external processor.