UI seems a little jank on iPhone SE, other than that, cool project. Q. How do you prevent racism, spam and hate speech?

A: you don’t

All of us humans are fundamentally racist, spammy, and have some form of hate in us. Depending on the state of society, it can suppress or bring it out. Anonymous boards like this bring out the worst in all of us.

Just as the current administration has catered to our bigoted, racist selves. Anonymous boards have more or less the same effect.