all depend on officer. website said need proof of flight ticket. In fact, my friend apply before covid 2018 they not asking about flight ticket. but my another friend apply on 2023 they asking proof of flight ticket
eg. Expired 30 january, you should go IO between 25 - 29 january to avoid any possible problem. In practice there is many people coming to extend on the same date as expiration date
Gettin long-stay visa for work is totally impossible, There is second option for you
1. Apply for tourist visa, stay in Thailand for 2 months + extended 1 months (1900 baht fee) then lf he found job that suitable for him. convert your tourist visa to become Non-B Visa (while inside / outside country) don't forget to bring all supportive document from your employer
2. Apply for Non-ED (Education Visa) from school, 3 Months + extended, then convert to Non-B Visa when he found job
3. Elite Visa (still need to apply Non B Visa)
4. Long term visa (LTR Visa) 5 years + extended 5 years