There are variations of the backside label, so it doesn't matter if it says something other than "Not For Resale"
Like I told you before, don't buy them if they don't have the back label. If they don't have it, they may still be real, but there's a much higher chance it's fake.
If they have the backside label, there's a good chance it's real.
The quality of the stickers may vary, but if it's really badly washed out than it's probably a repro label at the least. PCB color differences may be a bad sign, but I'm not positive if there are any variations. I'll have to check all my DS carts later and get back to you.
I can't really say for certain if any of those are fakes, but the Meloetta is a bit suspicious. It may be perfectly fine, but I can't really tell unless you'd pry open the cart.