Re: Downey's last?
I agree Timstuff and I think Marvel knows this. That's why they wanted the whole MCU in the first place. They can get more of their properties on screen and hopefully enough of them are successful enough to be franchises in their own right that they can stagger them in such a way as to give certain franchises that room to breathe whilst others fill the void. And they have enough viable characters to do this.
You know, it occurs to me that Captain America is basically the superhero equivalent of Mary Poppins. Practically perfect in every way and all that stuff.