Leaving the burs on the baffle do show a lack of attention to detail but the baffle looks very stout which would be my first concern on a 50 BMG. I think there is a good chance the Burs will go away after the first few rounds are fired. If not spend some time with a bead blaster, not that you should have to but if you want them gone before you shoot it I think that would work well.
I don't understand what the ringed 50 BMG brass has to do with baffle pic. Is this an integral can or did the can manufacturer also make the rifle? If you are having other problems the burs may be a tell tale sign of a lack of quality but I don't think they matter much in and of them self from a performance perspective but obviously hurt the intangible pride of ownership.