Easter eggs are hidden additions that don't belong but are added with a sense of humor. The .plane 118 falls into that category.
However, things like the kill tally in the B-29 tail gunner?
Not an easter egg. It's a nice little addition, but doesn't qualify as one of those. Things like "we like beer" on the goon is not so much an easter egg (it's right there in plain sight, no?) as it is a nod to tradition, to past herritage of the game. The troops are called "drunks" so it stands to reason...
Now, I would say the bottle of booze under the F4U seat might be an easter egg and a reference to Pappy Boyington's drinking problems, the TV show "Black Sheep" or any number of things

Flying over a remote part of the sea and stumbling across a godzilla head (like he's wading towards Tokyo)? Now THAT's an easter egg.