Hate to break it to you, but large and XL gates board from the second floor. So you will need to go to the right where it is labeled "G" and increase it to see the second floor and then build a foundation on top of your first floor. Secondly, baggage starts to become a problem with larger planes without an automated system. Third, you can research land purchasing if you hire a COO as well as research operations.
If these two ever want to expand, Planet Zoo will allow them to make a Shopping Mall with animal displays and a zoo inside (as well as either a trainservice or gondola canal).
I'm now genuinely curious to see how many games they can pervert into Shopping Mall simulations.