I like almost everything about these videos. It feels like you have a good group of characters and plot elements--enough for a fine comic book.
A few comments--constructive comments, I hope:
I think it would enrich the story if you added some words or concepts from a specific culture. It doesn't have to be from a specific tribe, just a cultural group like the Ojibwe or Cree.
I guess the counterargument is that you want the story to be universal. But universal means more general and less interesting. I don't think people are put off by more details. Just the opposite, I'd say: the more detailed it is, the more real it seems. Which makes it more interesting and involving to readers.
For instance, Cullen accidentally shot the baby and only Reggie knows he did it. Reggie doesn't just give Cullen the evil eye, he blackmails him to rejoin the gang. Cullen must decide whether he'll go back to the gang life or reveal himself as the shooter.
Or it could be something about reuniting with Tina and his baby. For instance, when he was a gang member, she got a restraining order saying he couldn't see them. Now he's not only afraid, he's physically barred from approaching her. But when the community sees he's reformed, she reappears to him. Because he didn't expect this, the ending has more of an impact.
It's like putting John Wayne or Harrison Ford or Tom Hanks into a gang. I.e., it stretches credulity a bit. What about giving him a tattoo or a piercing or something? If Cullen looks like a gangbanger but then reforms, the transformation will be more sincere and affecting.
For more on the subject, see Comics Good for Your Health and Comic Books Featuring Indians.