"1. Did America have better race relations in the year 2000 or in 2012?"
2012. Blacks felt much better after seeing a black man elected president for the 2nd time.
"2. Was there more rioting in the streets of America in the year 2000 or 2012?"
Neither.
"Who was rioting?"
Do you mean demonstrating? Do you call pre-game tailgating "riots" because occasional fights break out between opposing teams' fans?
But to answer your question - no one. Aside from the tea party demonstrations after Obama was elected, there wasn't really much going on in the streets until the Republicans nominated and elected a man who bragged of committing sexual assault and women took to the streets on 2016.
"Has it continued? Why?"
Some of it is to protest taking innocent immigrant children away from their mothers. And some of it is to counter-protest the recent rash of white nationalist rallies.
