Well Andy - isnt the 7000 a crop sensor too?
Yes, but you lose the DoF advantage of the FF sensor. Nothing more, nothing less.
and as a video editor with 20 years in the industry,
Well, I'm amazed with that experience you think changing frame rates is difficult! NLE in the video industry make 24p->25p totally painless. It just makes things 4% shorter and a slight pitch shift (which can be corrected if needed). If you want proof this happens, just go to amazon.com and amazon.co.uk, select two videos that are exactly the same and compare the running times. I did for the DVD version of Pirates of the Caribbean trilogy. Lo and behold, the UK version is 4% shorter than the US version (462mins vs 444mins = 462 * 24 / 25)....
BTW, I have close to 20 years experience in the digital video broadcast industry too
I stick by my assertion that it is far better to shoot at the correct frame rate in the first place.
Define correct frame rate? For the UK, it is 50 fields per second (even HD is broadcast as 50i, not 25p even if the source is progressive), for the US it is 59.94 fields per second, for the film industry, it is 23.976 frames per second. What do you shoot at if you want to make something that can be sold worldwide?
For example, even though I'm UK based, all my video is shot in 24p, but that's because most of what my media centre plays is 24p (films) so when I start playing my home movies, the TV doesn't resync to 25p when the video starts... And anything that is coded at 23.976p is sped up 0.01% to 24p. Again, simple to do. Anyway, it's a moot point as this is all about getting the Nikon video files to 25p/50i.
It is a relatively simple matter to speed up film, as its mechanical. Speeding up video footage is more complicated.
Assuming you mean digital video footage (and if it isn't digital, it very quickly becomes digital through a capture program), no it isn't - it's entirely predictable and very VERY easy! For 24p<->25p you just specify the output framerate and resample the audio. For 24p<->30P (e.g. US) you do 3:2 pulldown and leave the audio alone. Job done.