Could it be as simple as arrogant warmonger Tony Stark (from the original film) doesn't get hit by one of his missiles, and so doesn't get captured, doesn't build the flight suit, doesn't become iron man and simply falls down a rabbit hole of evil with Obidiah.

Then over time develops into the Dr Doom that we all know and love.

Always better to finish on a high when everyone loves you than go on for too long and be full of regret.

They definitely got it right. We have the whole 7 series on DVD (I know...right?) and we regularly rematch.

Trailers and teasers are the blight of audiences. When they aren't showing all the best bits of the film, they are showing parts of the film that have been cut, or worse- they are portraying the film as something it's not.

We should boycott them....

The problem with the multiverse saga is there has been no one for audiences to get behind. The most charismatic Avenger has been Dr.Strange, who famously does not play well with others

I think that bringing Loki in will give the audience someone who they can root for, and someone with the charisma to hold together a new Avengers team. I hope.

It's OK to recast the Avengers...or any Marvel character. It's the same as when a different artist draws them in different stories. Consider how Cap, Thor or Black Widow look between 1970 and 2000.