The thing about RealFlow is that it was designed for the movie/tv industry, where you have a fixed or minimal visual frame.
For example, the link you posted, looks to be from one of the Pirates of the Carib films, the sea state looks awesome, agreed but did you notice the resolution of the sea mesh being used.
The film used video renders set @ 30fps max but only produced a small enough sea section to fill the scene.
SH3 or SH4 on the other hand renders a 3D world around your location that extends KM's into the game (can't remember the exact amount). Importing anything produced from RealFlow will likely return 1-2 FPS. That's if you can find and manipulate the sea model and animation files, most of which are controlled by variables within the Scene.dat.
Don't stop trying though. A lot of ideas get poo-pooed first out, then someone manages to succeed where everyone thought it was impossible. This has always been the way with SH3. Good luck.
