Layer count is probably 2, view the gerbers.
Thickness is noncritical here and mainly depends on any clips, etc. in the blaster parts (which can be changed). Default is fine, likely.
They are probably all fine with 1oz copper.
By the way, I would recommend JLCPCB. They have been the fastest and cheapest I have used unless something changed as of very late, though I have no experience with PCBWay.
He's definitely using a magnified scope. A cheapsoft grade one should be more than fine. The world is awash in optics that are picatinny and with US shipping in a day on amazon or ebay.
I shoot offhand with an EOTech for that. I have done 100 foot wheely bin "bradley phillips" tests as a dry run of the procedure itself, and the fact that the optic is 1x isn't a big factor at that range in being able to aim precisely, it may help if shakey POA to get a table/bench to steady up on.
The scopecam, seems to be (as usual) something else optically from the actual sight. Mainly for gameplay downrange footage. For recording data out of game, try putting a camera near the target viewing the whole thing up close.
This is going to be a long one, but it ultimately makes sense to put all this data in one post, and it will be seen why. As such, I will kee...
I like that it defaulted to light on black. Vote buttons moved, threading indents are shallower. Site seems a bit buggy and does not work on my usual redditing client.