I want to request for change of visa (F2 to F1). I want to know if USCIS reject my request, should I leave USA or my F2 visa will be valid?
If the I-539 is denied, as long as your spouse is still in valid F-1 status, then your F-2 status should remain in tact. Another option is to apply for the F-1 directly at the U.S. Embassy in your home country.