Let me jump on the bandwagon of Buck being on the page.
Let's be honest, he needs his Tasha. I would love to either manipulate MCU or carry on with their Comic based romance. Modern-day here in NYC while he goes through therapy in their tiny apartment.
I could go strictly OC female, toss a bit of a history with a Lazarus-type line or someone he meets in NYC while making amends.
I also would adore Sharon Carter. Something about them sharing history would make things more interesting. Maybe set them up in Madripoor.