Yes. In virtually all domestic species, we need to be breeding for the health and wellbeing of the animal, not for oddball coat colors. We need to breed for brains & tractability/trainability, for good feet in hooved animals, sturdy conformation in working animals. And, more than anything, we need to breed LESS! That goes, IMO for humans as well as our animals.
There’s already an analogy to this: purebred show dogs and cats have been bred (genetically manipulated) for appearance at the expense of most other characteristics. Health issues aside, this also means they have not been bred for temperament or behavior.
Animals who have been bred for temperament and behavior (some working breeds, for example) and mixes/mutts tend to make better pets.
Pit bulls are one example – color is immaterial (with one exception: the “merle” pattern in pit bulls is associated with genetic flaws) but temperament is a paramount consideration. I don’t care what color my dogs are, but I’m overjoyed that they don’t pee in the house or kill the cat.
Not really. One of the limitations of selective breeding is that you get the whole genetic package of the animal, not just he desired trait. Which mean when you selectively breed for one trait, you tend to get a slew of other undesired or unhealthy traits as well. Genetic engineering however can stick in the desired trait by itself. There’s no reason why you can’t breed them for good health, and then give them green fur or whatever.