Thank you Trevor for your reply! I will definitely check the link you posted and I will also prompt anyone trying to solve the 1st question to check this series by Philip Galvan that shows ways to define airwalls.
https://www.youtube.com/watch?v=CoH9I4oZc_k
and these discussions here:
https://discourse.ladybug.tools/t/set-interior-wall-as-airwall/20901
https://discourse.ladybug.tools/t/im-quite-confused-about-airwall-in-energyplus/12012
The rest of the questions remain however!
