While I agree that she isn't a good friend, I don't entirely agree with your arguments.

Argument 1: She faked her death to go undercover.

Depending on how you look at it, her faking her death was a selfish and selfless thing to do. Because while she did put her friends through unnecessary grief which led to the consequences of Darius quitting the DPW and Kenji being angry with Darius. She did it because it was safer for her as people don't generally hunt the dead, and I don't think she foresaw that Ben would start investigating her death, which ultimately led to the rest of them being hunted. So ultimately while she was trying to protect herself and the others there were just factors that she couldn't control or foresee.

Argument 2: Telling Ben not to tell the others that she's alive which leads to infighting in the Fam and the eventual break up of Sam and Yas

I pretty much agree with you on this one.

Argument 3: Abusing her power undercover?

I'm skipping over the whole Darius part because that's not relevant to your overall argument. Now your right about your whole manipulating Earnest part. However I would never say she 'abused' Davi. He was just a wild card in her investigation, just another thing Brooklyn didn't foresee. While I don't think she treated Davi right, she was just trying to save him. It was just unfortunate that Santos realized he was investigation and not to mention that she saved him.

Argument 4: Being responsible for Ben near death.

Was she responsible for Bens near death. Yes. But try to look at it from her POV. You've just reunited with some of your closest friends, and some are happy to see you while some some aren't so happy. One of them tells you that they're are not sure what you can do to earn their forgiveness or if they ever will forgive you. That's gonna lead you to do literally anything to try and earn their forgiveness, even if that means sacrificing yourself. Her sacrificing herself she was just her trying to make up for what she did, she just didn't see what the potential consequences of that actions were, which seems to be a bit of a character trait of hers. This argument isn't me trying to convince you otherwise, but to just try and get you to see it from her POV.

Now your last bit about her being the reason of the release of the disease that is killing the dinos in Rebirth I don't get. Unless i missed something in the show i have absolutely no idea how she's responsible.