•what are some of the positive changes in south africa since the end of apartheid? what are some of the continuing challenges in the african nation?
•why do you think there are still so many problems in south africa even though apartheid officially ended 15 years ago?
•should people in the united states pay attention to what is happening in south africa? why or why not?
•does the legacy of apartheid compare with the legacy of racism in the united states?

To answer your first question, there are a lot of positive things about South Africa since the end of Apartheid. The most obvious being that races from all colors have access to better education and have an equal chance at getting work. There has been massive spending on infrastructure, making South Africa the most developed country on the African continent, including the building of speed trains, upgrading of airports, freeways, and hundreds of thousands of new homes for previously disadvantaged communities. The country went through an economic boom period since 2000, and because of good economic policies that govern our banks, South Africa did not suffer as badly as Europe or the US during the recession of 2008-2009, although there were also a lot of jobs lost. 

For the second question.
There are many, reasons why there are still problems 15 years after Apartheid. You have to keep in mind that there was a lot of damage done during the 40 years of apartheid, because of the separate development of black communities and white communities. But the country shows signs of improvement. Crime is one of our main concerns and especially aggravated crime. Although it does not affect tourists as much. The biggest reasons that there are still problems, is problems that are true for all African countries, and that is corrupt leaders that can't keep their hands out of the cookie jar (meaning that they only making themselves rich from taxpayers money, instead of delivering services). The other reason is the communist mentality of a lot of leaders. There are not enough taxpayers to cater for all the unemployed people. But like I said, there are many, many reasons

For the third ones.

I think the US should pay attention to what happens in South Africa, to pressure South African leaders not to follow corrupt policies. 

For the last one.

The legacy of racism in the US has a lot of similarities, but also a lot of differences. Remember that in South Africa, it was a minority government that used violence, intimidation to suppress a majority. It was also during the Cold War, and the South African government was against the communist policies of the black politicians. 
In the US, it was a white majority government that used to suppress a minority, but usually through exclusion and discrimination. Unfortunately, racism is prevalent all over the world, especially in Australia, Germany, and Britain. 
That's the end of my  very long answer.