Not quite understanding the rules, and can't find another post to clarify. Please correct me if I'm wrong on the following

I am allowed to open a door from the first image, but not the second image?

Thank you!

Correct. You can only interact with a door using the 2 spaces directly in front. Being 'next' to the door, diagonally wouldn't work either.

RRG says that the only spaces adjacent to a door are the ones sharing an EDGE with that door. This happens regardless the rule saying that the door is considered occupying all the EMPTY spaces that share an edge with it. During an attack this opens to a lot of inconsistencies, it's awesome! Also exploiting this in HotE with shielded class card is so amazing

When an ability asks about adjacency, you only use the rule that specifies adjacency to the door. Only the spaces sharing an edge with the door are adjacent to the door.

Only when an ability requires line of sight or distance from the door, you refer to the rule that says which spaces the door occupies.

Edit: Also look at the existing threads about doors and adjacency from these forums...

Just to add to the confusion, I think there's an item in the supply deck that would let you open it from the second picture

Also, how annoying is it that you can't place figures next to doors because of the bases!