Heh heh… well good, that didn’t take long! Lots of people get hung up this for a long time, but as long as they’re healthy they’ll leaf right back up, surprisingly fast as you’re finding out.
My vote on the holes is early life damage/rough handling. If more start showing up when you haven’t been at em in a few days then worry about it, otherwise I’d imagine you’re fine.
I don’t think you are anywhere near rootbound in there, but you are bumping up against the biggest problem with single bucket DWC, keeping up with the thirst. Just start researching Recirculating DWC, if they keep drinking like this you’ll be planning to make the switch before you get done I promise! Recirculating systems provide a lot more stability because you’re dealing with a larger volume of nutrient, and even with just a single control bucket you can add a float valve and gravity feed from a jug on a shelf outside your tent. Never go thirsty again!
They are looking great by the way, solid first grow you’ve got going man.