Can I remotely trigger a SUNPAC NE-i flash (dedicated for Nikon DSLR's) using a FlashPoint wireless transmitter & receiver?

Provided the triggering voltage of the Sunpak NE-i does not exceed the capacity of the Flashpoint (Godox) receiver to tolerate voltage, it should work in any mode for which the flash is capable when used directly on the camera's hot shoe. With two different third party products from two different makers, should doesn't always happen, though. At the very least, you almost certainly could fire the flash in sync with the camera's shutter using manual power mode.