I think its a good idea, but potentially difficult to keep concise. I think having something that said, "no racism, no sexism" that also included a brief sentence like, "This is community solidarity not charity" would be cool. What does everyone else think?

Also, it might be worthwhile to try an paint this on a piece of wood or on vinyl. Banners are hard to work with in the spaces we use and they also get soaked/fall apart easy, so it would be really cool to try and make something that is more durable.