This is the first I've heard of UKC issueing (sp) full priveleges on a dog that is not registered w/another organization. For instance, UKC will register as an apbt dogs that are registered w/AKC (as amstaffs), or the ADBA only. The AB must be registered w/ABA, NKC, NABA, or ARF first. I am assuming that the dog in question is intact. As a malinois, one of the 4 belgian sheperd breeds recognized by UKC, there may be different procedures. I know there are for showing, and licensing judges.
As to pup's temperament and conformation, I was told to look at these at 7 1/2 to 8 weeks. You can also check proportion at birth. Soleil was very suare at 8 weeks, w/nice angles. She's gone through some pretty grotesque growth stages, but as she approaches 1 year, I can see the pieces falling back into place. You're really not supposed to look at the dog too critically in the in between ages, but it's hard. There certainly are exceptions to this rule.