I can send mbt command with remove the "wiced_set_debug_uart( WICED_ROUTE_DEBUG_TO_PUART );" successfully. After download the application with HCI baudrate 115200, please plug out the kit from your computer and plug in again. Then I can send the mbt command.
For the download command, I also have the same problem as you. I recommend you to use the command line method to program the device if you don't want to use the SDK.
Please refer to part 2 of the following KBA "Programming using the command line" about how to program with command line. It is for the module product and also useful for chip.