u/Inevitable_Gap2066

I’m going to install inset led deck lighting around the perimeter of my deck. 1” cedar decking over pressure treated joists. Two questions:

after drilling the 1” holes into the cedar for the inserts, I was thinking to seal the inside of the hole with deck stain for waterproofing? Or a bead of silicone around the rim of the light before placing it down? Or don’t worry about it?
16” joists. Do people typically drill a 1/2” hole to run the wiring through adjacent joists? Use cut-n-seal? Or is that just more risk of rot long-term? if I run them down the side of the joists and then back up that’s probably 20-22” between lights. If I go through the joists that’s more like 3’.