I don't have the exact lines of programming from composer but here is a few things that hopefully help :
1) Definitely use room control driver. Will make your life so much easier.
2) For the LED's, you can program each source per the LED. When Audio Selection changes, If Pandora/IheartRadio/Whatever is selected, Then Set LED Current on keypad button you want.
3) For Cycling through sources, with room control driver It has either 4 or 5 sources you can choose in the driver properties and then connect the Audio Source Button to the room control driver Binding. It will cycle through the sources you have selected in the driver as you press the button.
Room Control Driver seems like your best friend in this project. It will save you countless hours of programming .