Why does any of that need to be addressed? Is there some scene where a smaller character makes out with a taller one, and so gets kissed on the head instead of the lips?
If not, I don't see the problem.
Also, averages and majority are just that. Doesn't mean there aren't exceptions.
I have not completed any romance in SW:Tor since I wait for the SGRAs, so I donīt know how much interaction actually happens.
But if interaction happens, like it does in other BioWare games, differences in the various models need to be addressed. In cut-scenes simply forcing a scene that is intended for body-type A also to play if the player avatar has body-type B can lead to rather silly cut-scenes (the ME2 examples can be found on Youtube).
And this does not only apply to physical interactions but also to verbal ones. To bring an example from DA:O Zevran will bring up a female Wardenīs eyes or a male Wardenīs strong hands in a banter with Morrigan if the player romances Zevran. The same is true for all other BioWare romances. To switch a romance from OG to SG more is needed than to delete the s from she and the wo from woman.