The only thing on my list (IMO) that is limited to a credit scene is The Skrulls/Secret Invasion tie-in, as it relates to WandaVision. Which on reflection, I shouldn't have even brought up, since we knew the Skrulls were still on Earth after Spider-Man: Far From Home.
And you're right - maybe because I have a background in the comics (a lot of the plot beats from the MCU come from my wheelhouse of comic reading in the 80s and 90s) - I see/know the potential of where these stories might be headed, to know that they aren't just a throw away.
We know that Armor Wars and Secret Invasion are happening. John Walker is clearly not going away (they would have locked him up, not let him go). Yes, there's potential there between US Agent, Val, and Zemo. And we don't know what the plan is, but everything is pointing in a direction for the Thunderbolts to happen. Those are definitely threads that are being left open. Ralph Bohner might be a red herring. But with a film call "The Multiverse of Madness", and Scarlet Witch involved, and Spider-Man having multiverse shenanigans as well, there's a real possibility there that he isn't a red herring.
I don't know if you remember, but Marvel came under criticism years ago, with The Mandarin and the Ten Rings (Iron Man 1 and 3). They even made a short to sort of answer the question about Ben Kingsley's character. And where are we know? Months away from a movie with the "real" Mandarin as the antagonist, and his organization - the organization that is, to a degree, responsible for the creation of the Avengers!
I understand the skepticism, especially if you were a fan of the Netflix series, or Agents of Shield. Those didn't pay out (unless you believe the rumors that Daredevil, Jessica Jones, Punisher, and Kingpin are coming over).
Thank for posting those, because I completely missed them, and they are 100% on target. Bucky's journey alone was incredible to watch.