With a pending EB-5 I-485, a valid F-1 visa and AP, which one should I use while reentering the U.S.?

If you want to keep your underlying F-1 while I-485 is pending, do not travel. If you need to travel, must reenter the US on AP and will be a parolee until I-485 AOS is adjudicated.

You must use the advance parole document when seeking to be readmitted to the U.S.

If you do not travel, you can keep your F-1 status. But if you do travel, you will need to re-enter on your AP.

AP now that I-485 is filed as F-1 is a nonimmigrant status and the I-485 clearly indicates immigrant intent.

Must use AP and you will no longer be in F status.

If you leave the country, you would need to use the Advance Parole document. Otherwise, immigration would understand that you withdrew the I-485 case. However, by reentering the country with the Advance Parole, your student status will no longer be valid. In other words, if you want to protect your student status while the EB-5 and I-485 are pending, you should not leave the U.S.A.

You should use your F-1 visa to reenter the country in F-1 status. Entering using your advance parole document will cause your F-1 status to be terminated. So long as you already have advance parole when you depart the U.S. in F-1 status, reentering the U.S. using your F-1 visa will not jeopardize your pending I-485.