Uncertain About IRS Student and Dependent Status

Our son worked at an Americorps' related nonprofit organization from January through part of June, 2022 in Portland, Oregon. He returned home to Torrance, CA. in August, and started a Master's degree graduate school program in September. I understand that the IRS considers a person as a student if he/she attends a college for part of any 5 calendar months of the year. 

1) So he is not considered a student (for Turbotax occupation question) even though his college considers him a full-time student, and will be a full-time student for at least the next 2 years?

2) If he is not considered a student by the IRS/TT, do we answer the "occupation" question based on the job that he had earlier in 2022?  While taking a full-time student class load, he is also working on campus part-time.  Should his campus part-time job be considered his "occupation"? 

3) If he is not considered a student according to the IRS/TT, does this affect the reporting of a 1099 Q form received from a 529 for qualified educational expenses? 

4) He turned 24 years old in 2022, so he can no longer be considered a dependent, regardless of the amount of support we give him?  

 

Thanks.