In the suggestion there, Bool All True would be on the Trigger.
That is the locked door right?
This is another element to the whole door puzzle that I have a difficult time wrapping my head around.
#1 Does that mean I create two local bool variables that are true?
They start as false. If you do have the key, they should be true.
#2 What about the keys/objects since they have the standard trigger event, send event, get parent, destroy actions that a regular pickup item would have.
I don't know what you mean here. The only thing that needs to happen is very simple:
Create a bool for each key you need.
When the item is picked up, change the bool to true.
When you touch the trigger, check the bools that are required to unlock the door.
If they're all true then you must have all of the keys, so continue opening the door.
If any are false then the door does not open.