1. What one religion may consider immoral (burning a widow alive) another religion may not.
You are kidding right?
2. Again, it's a religious-based morality argument. What one religion considers immoral, another does not.
In general the answer to that question is no. Basically, other than a very few exceptions you are just plain wrong in this statement, morality is fairly consistent across religious traditions. This is one of the reasons for the moral argument for the existence of God.
3. So Martin Luther King Jr. fought for equal civil rights based on his religious background, not based on race?
Yes... and both... you are however picking the obvious example from a list since it "seems" to make your point. A bit obvious don't you think?
4. If this is the case, then Christians would build these things based on compassion. The idea of morality and religion should never come up. Christians would build schools for people of a different religion without ever trying to push the Christian faith.
They do
5. You were saying that missionaries fought corporate and governmental greed and corruption. Did the missionaries do that without trying to push the Christian faith or trying to convert people?
You act as though conversion is intrinsically evil... sorry I don't buy that. Did they protect only those who converted or did they use their advocacy as a tool of coercion would be a better question and the answer is that in general (I have not met nor studied the history of every missionary that has served in the last 2000 years) the answer is no.
6. You're saying that if there was no religion what so ever, that the donations to non-profits would drop dramatically? Is a person immoral because they don't donate to non-profits?
Yes, I am... supported by fact in this... from the Hoover Institute-
"To put this into perspective, religious people are 33 percent of the population but make 52 percent of donations and 45 percent of times volunteered. Secular people are 26 percent of the population but contribute 13 percent of the dollars and 17 percent of the times volunteered."
I did not make a claim of morality, though that could be argued... rather the issue is the common good of a society and the world as a whole.