Very nice! As I've always said, the PSR-E400 series keyboards are far more capable than many people give them credit for. I also use the harmony tremolo and echo effects for delay/LFO type effects for some of my sounds.
Around 6:20-6:39 in the video has a very Vangelis type of sound.
He said that his techniques can be used across the PSR-E line, but he was using the DSP effects quite a bit, which are only available on the PSR-E453 and E463 (and their EW400 and EW410 76-key equivalents). But still, with the other suggestions about using the envelope and filter for the dual voice, as well as using the arpeggio function, there is still plenty of good advice that applies to the whole line of these keyboards. The only problem with using the data-wheel to control a specific parameter is that you cannot program the function of the data wheel to a registration, so it would be difficult to use that feature during a live performance when you're switching between registrations. But it could still have potential when playing in a band or doing a multi-track recording.