Answer:
I don't know if this is genuine curiosity but I'll try to provide a full explanation for all questions
22+22=44
The confederacy is viewed as racist by many because it was created as a pro-slavery group. Through being pro-slavery they were being oppresive to African American/POC and viewed these slaves as a lesser form of a human when in reality, they were still people. Those who still celebrate the confederacy and state that the confederacy is the "ideal America" are either being ignorant to what the confederacy stood for or are unknown to the atrocities that the confederacy committed. The confederacy also only existed for 4 years while America has existed for 244 years.
The statement "all lives matter" doesn't neccesarily mean anything wrong. Because it's true, all lives do matter and need to be respected and treated with equal respect. However, the all lives matter movement was created after the black lives matter movement was created. In essence, it was made to silence those who were speaking out about the unfair treatment to Black people through the police force. Because of this the all lives matter movement is frowned upon because instead of speaking up about problems that are specific to people of other races it was made to silence black people specifically.
If you are serious, continue to ask questions and form your own decisions! This is obviously my side of view as it is still considered controversial but I hope it helps :)