“그리고, F-1으로 tax return받은 것도, 국세청에서 인정이 되나요?”--->I GUESS as long as you paid income tax(es) on your income that you earned as a H1B visa holder/ a F1 visa holder to the IRS, under the tax treaty between US nas Korea, you May claim tax credit)or deduction) on your US taxes on your Korean return. So, please contact a Korean회계사, 세무사 there in Korea,OK????