I'm a strong believer in selective breeding, and with the success that spiders have as a morph vs the extreme cases, I really feel comfortable working with it in the future. As for the others? It wouldn't prevent me working with them if I were to add them to my plans. The known lethal combos (spider x sable) I'd simply avoid. If I really liked a certain combination and there were known healthy specimens I would be comfortable taking the risk.