I think a lot of foreigner may have a lot questions on Korean tax system and no idea how to approach to get an answer.
The below web address is an address you can visit and ask a private questions to get some very official and exact answer on your questions.
Please click it and enjoy it by yourself; https://www.nts.go.kr/eng/help/help_21.asp?top_code=H001&sub_code=HS02&ssub_code=HSB1
Korean Tax Rate
Korean tax bureau
Housing Lease Protection Act
FDI Liaison Office Establishment
Stimulus payment to foreigners
Corona Subsidy in Seoul