Yeah I was slightly disappointed in the season. I think they should have went with Typhoid Mary as the villain. I kept thinking she was going to show up. Maybe they will save her for season 3.
I'd rather see Typhoid in the upcoming season of Daredevil and to keep her around and not kill her off so she can be a shared villain between Matt, Jessica and Danny. (Luke is borderline fireproof and swordproof so she honestly can't hurt him.)
Trish will likely become a vlogger making a living off her podcast, corporate sponsors and Patreon. She'll be covering crime in New York which puts her in danger, more so since she's spending her nights dressed up as Hellcat. After she gets kidnapped, Jessica is forced to bury the hatchet to rescue her friend from gangsters (and see if Disney can borrow Man Mountain Marko from Sony since if Spider-Man fights a gangster, it'll more likely be Silvermane, Hammerhead or Tombstone). Denny Haynes is the main villain who is using Marko to harvest Trish's DNA and sell her IGH-mutated blood to the highest bidder. Base the main plot on Alias 16-21 with Trish filling in for Mattie Franklin. IGH would be revealed to stand for Inhuman Growth Hormone. It's a process by which people would be implanted with inhuman DNA to gain powers. The biggest complaints about Season 2 are that it isn't based on a comic storyline and lacks a strong central villain. Haynes would be introduced within the first four episodes and would drive the plot.
Malcolm will be busy working with Hogarth. Hogarth will hopefully be cured during Iron Fist Season 2 by Danny. (Or Alice Eve if she's a gender-swapped Orson Randall.) Hogarth is hired to represent Haynes and that puts Malcolm in a situation where he's supposed to sabotage Jessica's own investigation to find Trish. Hogarth also owns a cryo storage unit housing Killgrave's body whose skin has turned purple after being frozen. If Hogarth isn't cured yet then she gets cured by using a sample of Trish's blood purchased from Haynes and Haynes hires Hogarth to get Pryce Cheng to kill Jessica. Hogarth would eventually betray her own client after forcing him to pay her and then leaking tips to Jessica.
Oscar will be killed to free up Jessica to marry Luke. As Jessica closes in on Trish, Oscar is kidnapped, tortured and killed along with his son while Luke appears at the end of the season and marries Jessica.
Dorothy is the one who hires Jessica to find Trish. Jessica doesn't want to do it at first until she realizes that Hellcat is Trish and Haynes' public unmasking is going to put Trish in danger for the rest of her life. Haynes is currently filling Trish up with drugs and using her as a sex slave, basically doing to Trish what Killgrave did to Jessica. Jessica gets a whiff of the type of designer drugs that Trish is being fed and that causes Killgrave to resurface as a new persona fighting for control of her mind and attempting to force her to ressurect him out of cryo storage with Jessica' drinking only making his voice that much stronger.
Jessica defeats Killgrave in the third to last episode by seeing a shrink who puts her under hypnosis where they have a battle within her mind. Jessica defeats the persona Killgrave implanted in her and manages to overcome her split personality. That alongside cutting down in drinking which will be shown to be a season-long struggle for her.
The end of the season sees Jessica free herself from Killgrave's control by getting her drinking under control. Jessica calls Luke over and Luke assists a Jessica who is still grieving for Oscar and the two of them hook up before they assault Haynes' warehouse. Jessica gets over her anger towards Trish and realizes that she's the only family she has left and this is the night when she's going to be unmasked. Jessica informs the NYPD that Haynes' is holed up in a warehouse in Harlem and Misty Knight is dispatched to help with the situation. Jessica decides that she herself is going to suit up. First as Nightress but then realizes that she's already been a public superhero three times in a row and defeating The Hand already put her in the spotlight so she's going to wear the Jewel costume that Trish once made her. Jessica, Luke and Misty attack Haynes' base alongside the police and rescue Trish but not before she's unmasked on a live stream in front of the entire world.
Jessica tells Trish that she never wanted to see her again and she isn't there because she likes her. She's there because Trish did something reckless and stupid. Trish just responds by giving Jessica a hug. She's crying but doesn't say a word, she just lets Jessica vent and then walks away.
The season finale has Jessica learn that she's pregnant with Luke's baby. Trish can no longer be a media personality now that everyone knows that she's Hellcat since every criminal out to make a name for themself is going to want to kill her and she'll have to join Alias. Jessica avoids being bought out by Hogarth by allowing Rand to buy Alias. Misty also resigns from the force and Luke reveals that he just got a private investigator license. Luke tells Jessica that Danny isn't a fan of the name Alias Investigations and decided to rebrand. The new name is Heroes for Hire. Luke tells Jessica that if she's Jewel, he's now Power Man and proposes to her. Misty says that she doesn't do codenames (Danny and Colleen are also mentioned to have joined up but Matt decided not to join, Elektra reached out to them but nobody trusted her and nobody trusts Frank Castle to not be a loose cannon). The phone rings and Jessica learns that Kilgrave's body is missing. Jessica must have freed him while sleepwalking (or at least she assumes that). The final scene is a purple-skinned Killgrave breaking the fourth wall, telling the audience to put down the remote and to hear him talk about how great it is to be alive again.
That's how I'd do Season 3. Base it on the actual comics, make it a mystery with a recurring central antagonist, turn Trish into Hellcat and find a way to bring Killgrave back. Season 4 would reveal that it was another of Killgrave's victims who brought him back to life. Somebody who loved being under his control and formed a cult in his name. That's just how I'd handle it.