In those days, "world" meant everybody living in the Roman Empire. Remember the emperor declaring that "all the WORLD would be taxed"? I didn't hear about the assessors/census takers going past those borders.

As to Jesus Christ's claim to be the ONLY way - well, how can he be his own authority? Can anyone be his own authority? Couldn't I present a set of teachings, and then claim, that I am the only way, too?

Animals feel pain & suffering just as we do, and they value their lives as much as we value ours.