Your video has great color and saturation.
Oh I agree. You most likely never need a filter for photos as you can adjust the camera to get the correct exposure.
And yes, of course filters for that cinematic effect. Although I don't really find the absence of motion blur to be very objectionable or even that noticeable.
I have not experienced the jello effect so I can't speak to that with any authority.
A graduated ND filter could be useful more than anything in many cases, but I don't know if anyone is making those yet.
I just think there is a filter bandwagon that many are jumping on without having a good reason. Not everyone who buys a Phantom is a photographer and it would best serve those to get the basics of photography, video and composition down first before complicating things with filters.
Here are a couple options for graduated filters.
DJI Phantom 3 Graduated Filter Set
P3 Series Filters