the issue of equal amount of screentime was the major concern since this movie started developing...and I am sure that Whedon, being a fanboy himself, will obviously tackle this problem...
as long as they make Cap gain each avenger's respect and be the leader, the fans will be fine
An article in Empire magazine addressed that issue. Whedon was worried about equal screen time but said the reality was much worse..."they would not stop chatting, giggle, giggle, giggle, chat, chat, chat." lol "But every single one of them was rooting for each other"
The article also address the RDJ issue...Whedon promises "its a full ansemble" etc.

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