Same

He's made a lot of comments over this and by a lot I mean enough to try and convince people the film acts on "it's own". Why though? I mean is it because he wants it to be left as a surprise or is it because he's crafted this film so well HE wants it to remain separate.

I just can't believe him, I'm sorry but it exists in the Marvel Universe, they are Marvel characters and Thanos, the main villain for the Avengers in the third films is the background villain in Guardians of the Galaxy. Put 2 and 2 together. Anyway it's pretty obvious higher ups at Marvel will make them team up in the future.

There is no way the Avengers can take on Thanos by themselves, it seems they are already struggling with Ultron by the looks of the trailers

Hell even if you have Avengers, Guardians, leftovers of SHIELD and the inhumans it still doesn't seem like enough man power for this mad titan with new found infinity power.