I haven't assumed anything because a dog is from a different country. In fact the import that I have do share some of the same dogs in their lineage back a number of generations. You should have noticed that it was chosen over the other breeder because the breeder has done testing. The "local breeder don't test and doesn't know what any of their dogs might have. They can have these genetic diseases or be carriers and never know it or in some cases they don't care. As far as the COI we have a calculator for our breed to see the COI before ever pairing dogs to see if if it is too high. Of course I've seen breeders that do number on what I would call the extreme side. I have avoided them. Again it goes back to what I said previously research the breeder. TO clarify my statement about taking chances is not about risking breeding to a disease dog. It is that if or when I choose to breed to a dog outside of what I own I might take a chance on breeding to a dog that has not been tested. If I know a dog or lineage has some type of disease I'd stay far away from anything that I know come from it or that has produced it. 

Regarding dogs being show dogs. Anyone can show a dog. It is not an exclusive club. They all share the same genetics as any other dog. Diseases or not due to showing a dog. Just as inbreeding is not exclusive to show dogs. It happens in every dog community. In fact it is extremely present in those that abhor anyone the shows a dog and only praise dogs that come from what they call working lines. Many of them have never done any health or genetic testing. It might even be hard to find enough of them that have regularly visit to the vet. They still feed big name commercial dog foods that are not nutritional to the dogs.

I do see a problem with people using certain dogs. I will not contribute this to one group of people such as people that "show" or people that only "work". What I have personally seen is that all groups do this. The want the popular sire. That sire might have done well at something. It has a name. Everyone has frozen semen. Many claim to be the only one that has semen. But everyone claims it is the sire of their next litter. No one talks about how that dog dog died a mysterious death at a young age. I'd avoid anything with its semen. Sure it has produced some nice looking dogs. But I'm unsure of how healthy they are. Especially know that every dog in its litter dies young and many of its offspring has done the same.