Is there a mounting bracket for the ST200 amplifier?
The amplifier does not use a mounting bracket but has a small "bracket" attached to the bottom for mounting.
Does it come with plug and play wiring
There is a harness that plugs directly in to the motorcycle amplifier. The other end are loose wires to connect directly to your battery and motorcycle speakers.
How many channels does it have? can I play with sound balance between front and rear speaker? is It water proof?
The ST200 Amplifier has 2 channels and it is not waterproof. You should take a look at the ST400 Kenwood amp for those features.
Will it play the music from my phone if connected with USB? Pandora?
This amplifier will play the music from your phone, including Pandora, using the headphone jack. You connect the plug to the headphone jack of your phone and the other end plugs in to the amp. The USB port is for charging only. You can also add one of our Bluetooth controllers for a wireless connection from your phone.