Looking for advice on hiring a foreign English teacher in Gangnam! Can anyone help with contract review and recommendations?

Hello! I'm a foreigner who has been living in Korea for a year now. I recently got a job as an English teacher in Gangnam, and I have a few questions about the contract that I would like some advice on. I'm planning to commute from Yongsan, which will take about an hour. The academy in Gangnam where I'll be working as a full-time English teacher has working hours from 8:30 am to 6:20 pm Monday to Thursday, and until 3:30 pm on Fridays. There is a 30-minute lunch break, and an additional 30-minute break on Monday to Thursday. The contract states that I must be at the academy during break times, but they mentioned that simple outings are allowed. The salary is a base of 3.3 million won with a housing allowance of 700,000 won, totaling 4 million won. The housing allowance is paid in cash and is subject to taxation. Overtime pay is 20,000 won per hour, and there may be additional classes on Fridays. During the probation period, only 90% of the salary is paid according to the contract, but the academy actually pays 100%, and this clause cannot be removed. National health insurance, pension, and taxes are paid according to the law, and retirement benefits and visa support are provided. Annual leave is 15 days. Does anyone have a similar experience? I'm worried about the long working hours, commuting time, and the probation period salary clause. Any advice would be appreciated!