Hi Pert...yes agreed a lot of activity for sure.
Anyway, I’m not using anything connected to the board such as shields or any wiring...just the board as stand-alone as pulled right out of the starter kit box. I place it directly on top of its little box to ensure it’s not sitting on anything conductive.
As for the L LED, it never blinks when hitting the Reset button(or plugging in usb cable). Stays solid yellow.