Wait, so the oppressed aren't expressing concern for their oppressors? How inconsiderate of them.

The point being, of course, that we're all oppressed by the system. Some more than others, certainly, but if you go "well we're oppressed the most so this is about us" then you exclude a large number of people who are also oppressed.

A just society is better for everyone, even the people who aren't getting murdered by the police. Not sure why that's so hard for some people to grasp.
People grasp it. What you fail to grasp is that a "just society" as you put it is not going to happen so long as the system remains in place.

The system needs to be changed so that it's not racist.
This isn't a million miles away from saying the sky needs to be changed so it's not blue. The only difference being we can actually overthrow the system, we can't overthrow the sky. But if you think we can just change certain parts of the system while keeping it in place, I think you're in for a shock. The system wants us divided, so why would they change anything?

You don't need an entirely new system for that
I disagree in the strongest terms. The system is not racist by accident. It's not white people being racist, it's wealthy people keeping the masses divided. How are you going to change that? You probably don't even believe it. How can we change the system when we can't even agree what'#s wrong with the system?

1) individual police need to be held responsible for breaking the law, not given a pass because the victim belongs to a minority
This is technically already the case, the legislation exists. It's just not the case in practice, as they exploit loopholes, fake evidence, plant guns/drugs, whatever they have to do to look out for each other. If they do a good enough job of protecting themselves, how can we prove they did it? This is really easy to say but really difficult to do.

2) the police as an institution need to train people properly so they don't default to the use of excessive. If you do those two things, 90% of the problems with cops abusing their power would be solved.
Again, easier said than done. The police need to be trained how to use a gun, how to defend themselves, how do you "train them properly" so they don't use excessive force? Tell them not to use excessive force?