1. You're still thinking from within the JW perspective when you ask the question of which is the "right" religion. Why does there have to be a right religion at all? Or why can't several be right in part, and you have to take what you from each and can combine them?
2. A great number of churches have spread internationally despite racial barriers. There are Catholics on every continent, the Pentecostal churches growing in the United States and in Ethiopia, and the church I attend with my family has links to churches in India and a Hispanic church in the ghetto of Buffalo.
I would also challenge you and asked what extent race isn't a factor to the witnesses when there is only one minority on the Governing Body, and he's still American, to my knowledge. No Latinos/latinas, no Asians, no Indians, no Native Americans, etc.
3. I've never stood outside of the convention to protest; I see this as ineffective and frankly rude. However, the benefit of doing this is helping others, from our perspective, regain control of their life. People should not be scared into shunning their children, or letting their children die if they need a blood transfusion, or told the college is a false refuge of Satan, that masturbation is a secret sin, that independent thinking is of the devil (all of which I've heard at assemblies and in fact have on tape).
4. A good response to the claim that "the light got brighter" is that a group that has always claimed to have "the truth," the whole truth and nothing but the truth, is deceiving itself or others, for if your beliefs have to change, that means you did not have or teach the truth in total at some point,
A good example is the Watchtower article in which the revised understanding of the faithful slave was put forward. The article states at the beginning, "our spiritual relationship depends on us accurately identifying the slave." If this were true, than any JW who died before that magazine came out is doomed to annihilation, as they did not correctly identify the faithful slave as the Governing Body. New light is inherently contradictory for a religion that claims to be 100% right all the time.