As for your custom icons, you can use a button command to switch the image.
Make 2 images for your play and pause icons, like PLAY.jpg and PAUSE.jpg and put them into your skin folder. Then have a button on your skin with this command.
Make sure it is the very 1st button in your skin file.
Now it would load the image at the location x=10, y=10 the width=50 and the hights=50.
You push the button once it plays and loads the play image, push the button again it pauses and loads the Pause image.
As for the indicators, you must have the on image on your ON or DOWN skin picture and place the indicator over that area.