I tried unhooking everything first and no odd sounds. My learning is a bit crippled through depression, although that installed[] array helps visualize what pins do what. It directs pinMode in a latter loop. The stuff is tabbed with whitespace to allign everything. Its a lot of crap IMO below.
"It may be a combination of things" - that's what I fear. It is somehow correlated to the blinking of LEDs. They blink and the thing emits a strange shriek akin to the "most annoying sound in the world". The speaker isn't passively driven, it is driven by a PNP transistor the gate is attached to A0 through 220ohm resistor. I used a PNP as it suited the installation much better to go against ground for the speaker.
I've been safe with the board, only took a solder iron to it for 2 seconds total, have a ground clip dangling and ground plane throughout a paperboard sandwich.
Thanks for taking your time to look at it.