I have been working on a run with the Europeon version of the rom(50 fps), but have been running it at the American speed (60 fps) on Gens. As far as I can tell, the Europeon and American roms have only two differences: The Euro version has the Virgin logo at the beginning and it also has a language option. This has no benefit to me, nor does it cause any problems. I ran the Euro rom at American speed vs. The American cartridge on a Genesis console and both run at exactly the same speed.
The reason for this: I didn't realize there was a difference until only recently when I tried out the American version of the game and noticed that the logo and language option was missing. I'm about a 1/4 done with the run and it has been bothering whether or not this is of concern. I may be worrying too much, but I had to check. Should this be of question?
[Edit] Okay, let me rephrase it: Is it okay to run a Europeon rom at American Speed?
To run the movie with the correct rom, all you would have to do is click on CPU and change the country to USA (NTSC). It should be fine then.
