I am on a student visa pass holder. I graduate on June 1st, and hence, according to ICA, I must surrender my VISA within 7 days and cancel it, so I must cancel it before June 8th. Upon cancellation of the student's pass, a temporary visit pass of maximum 89 days will be grated by the ICA to the student, if they are residing in Singapore. However, the temporary visit pass will become null and void once they leave Singapore within the granted period.
And I think, that in this case, some nationalities will need to apply for a Visa to re-enter Singapore.
Here is my situation.
I was planning on going on a graduation trip overseas from the 5th to the 9th. However, this falls outside the ICA's given time period.
Should I surrender my student visa pass before then, and then be issued a temporary visit pass and leave on the 5th, and then re-apply for a visa to come back on the 9th? I don't really know which procedure I should take there.
Or should I leave on the 5th without having returned my student visa yet, and then come back on the 9th and just pray nothing bad happens?
I'm really hoping not to cancel this trip. Please help

(also: does anyone know if Koreans have to apply for a Visa to re-enter Singapore?)