The wording of your first question is very difficult to decipher. Why do I say this? Because there are characters in this story that are not racist, there are characters who are the victims of racism, and there are characters who ARE racist. As a result, there cannot possibly be a "single quality of racism" that all of the characters in the story experience. However, I am pretty sure that by saying "these characters" you mean Fonny's family and Tish's family.
If you mean the main characters, the wording is STILL difficult because racism is racism, and there are other forms of prejudice that both families experience. I am going to be more general and say "prejudice" just because I want to include religious judgement in the mix as well.
With all this being said, the answer to your first question is that the "single qualit[ies] of [prejudice] that these [main] characters experience" is that of white being prejudiced against black and that of the self-righteous being prejudiced against sinners.
Fonny has an honest white man defending him in court: Hayward. This young lawyer is savvy, and he knows that Bell, the officer and main witness of the prosecution, is both a liar and a racist. Hayward knows that Fonny doesn't have a chance unless Hayward can nix the state's case.
We have to disprove the state’s case. There’s no point in saying that we have to make them prove it, because, as far as they’re concerned, the accusation is the proof.
This is a perfect instance of racial profiling and racism being the reason behind that profiling. Luckily, the story ends with the hope (although only the hope) of the innocent Fonny being set free.
The prejudice of the self-righteous against the sinner can be seen in the character of Alice. Frank Hunt's wife, Alice, is livid because of what Tish "did" to her son, Fonny.
The Holy Ghost will cause that child to shrivel in your womb. But my son will be forgiven. My prayers will save him.
Any devout Christian should see this as HORRIBLE and truly un-Christlike! First of all, the Holy Spirit would never seek ill will for any soul. Second, she is praying for harm to come to one person and safety to come to another. She attributes this amazing action to her own power of prayer. The irony here is that Alice is so self-righteous that she fails to see that SHE is a major sinner and forgets that she shouldn't judge others. Further, she doesn't attribute the power of prayer to God, she attributes the power of prayer to HERSELF. Such is the sin of selfishness.
In regard to your second question, the addition of Tish's and Fonny's pending child unifies the families (apart from Alice) and they stand together in the face of racism and prejudice. They stand together against the false accusation against Fonny. They stand together in happiness for the new life that is about to come into the world. Further, there are different types of family love that are involved here, all unified by the pending birth and support of the innocent Fonny. There is eros: the love between a man and a woman (exemplified by Tish and Fonny).
I was in his hands, he called me by the thunder at my ear. I was in his hands: I was being changed; all that I could do was cling to him. I did not realize, until I realized it, that I was also kissing him, that everything was breaking and changing and turning in me and moving toward him.
There is filial love (exemplified by Sis and Tish), there is familial love (exemplified by pretty much everyone except Alice), and there is platonic love (coming from Hayward due to protecting the innocent).
In conclusion, perhaps we could say that, if we add them all together we have the ultimate love: agape love. This is the unconditional love that God shows toward all of us and, ironically, the love that Alice is so very far from. As a result of all of this unconditional love (apart from Alice), the family STANDS TOGETHER as their response to the quality of racism.