smd leds doesn't use that much power so a switch is not necessary just for turn it on and off
for leds in buttons you could drill and put leds in or use this method
Click HereTriggers you could just put leds there and they should show through the plastic if know scrap the plastic alittle you could use hot glue to hold it in place
for the soldering points you could the positive for power leds and theres letters BT+ thats another positive and negative a you could just scratch the paint and solder there
heres the tutorial for sound reactive on dsl
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