you can only get your non imm O based on marriage stamped into your Norwegian passport as that is your nationality and you had to supply your marriage status documents from Norway. If you enter with your Irish passport your Thailand entry stamp would be in that passport. Immigration cannot enter your non imm O visa into your Norwegian passport as it does not have an entry stamp and they cannot enter it into your Irish passport as your marriage documents are from Norway. Only option is to enter with your Norwegian passport.
there is a difference between a government approved quarantine facility and home isolation. The CDC quote is for home isolation not a quarantine facility.
Fresh air does not disperse the virus, air flow does. But as you are alone in your hotel room you do not need an open window for air flow as you do not want to disperse the virus but contain it.
In the case of home isolation the CDC recommendation about open windows is aimed at preventing people in a household with a infected person transmitting the disease. Airflow is also an effective way to prevent transmission in a work environment.
Two different concepts for different circumstances.