Ok this one is super quick. I hooked up the last of the wiring (except for the Neopixel to SPI because I may put a resistor in eventhough it already runs through a logic converter). Put the batteries back in which have been sitting charged for WAY too long and turned it on and.... it turned on.
Well, the power switch I had used a dozen or so times before one of the pins kinda melted/lowered it looked like so it wouldnt turn off. So after safe powering down the Pi I had to disconnect the battery. But to fix I got a replacement identical switch (again because I had used that same switch with no problems before) and added a 20A inline auto fuse. Doesnt seem to be a problem and was probably just a bad switch, but there was no bam, bang, kaboom or exploding lipos so I will consider that progress.
Still have a couple of panels missing & of course all the programming. But it's summer here, Im trying to stay cool.