I think with all these add ons for SketchUp it is very important to keep the interface as simple (and close to the native SU interface) as possible.
some sort of slider bars would be a nice idea.

I would prefer, if you are able to adjust the interpolation of camera movement and the transition of traveling speed independently (to do fast accelerations in some points). another slider to choose a specific time for each scene would come in handy too (perhaps a check box like "keep traveling speed" could change the scene time automatically, to match the traveling speed with the previous scene, if you wish a continuous flight).
one could even consider to have an additional slider bar for the transition of camera focus (so that the camera either does one fluent movement or keeps its focus on one point and then quickly pans to the next point of focus).
in order to have advanced control of the camera focus it would be very nice to be able to add a scene in-between two others, which is placed halfway on the interpolated camera path (and with halfway interpolated orientation). thus you could simply change your focus point and update the scene, without changing the camera movement at all...

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