I think the humor works depending on characters. The levity works for me personally because each film has some gravity to the plot (planets being destroyed, bad guys getting MacGuffins that will give them some form of power, people dying or getting severely injured etc.) and it's nice to have some humor. The Avengers nailed the balance between the two, in my opinion. And for characters like Spiderman, humor goes hand in hand with the character. I thought it was odd to have so much humor in Thor: Ragnarok, particularly the scene with Surtur, but I still enjoyed it way more than the first two Thor films.
That said I hope Infinity War doesn't have much humor in the big battles. Maybe some smart mouthing from Spidey and some quips from Tony Stark but not much more, please. We're dealing with cosmic annihilation, after all
Agreed.... they had to do something different from the 1st two Thor movies, so I think the comedic elements - while a little over-done and over-the-top at times - were just what the doctor ordered. As for the other humour moments, you're spot on that it should largely be left to Spidey, Tony, Starlord, Rocket and Ant-Man (though, I don't know enough about the comic-book character to know if Rudd's comedy value/delivery is true to the character). Too much from others (like BP, or Cap, or Dr. Strange) would feel forced/out of place.
The comments during the Civil War airport scene were perfect, imo. "I didn't carbon date him!" lol
Adam Warlock isn't in the movie.
How do you know?
'cuz it's been repeatedly said that they're saving him for GOTG 3.