Things like the exterior starship scenes. How was that done? What software was used? Can it be replicated in a mod?

I imagine they used a program like 3DS Max, Maya, etc to render out an animation using high poly models of the characters(for things like the Revan revealtion movie) or objects(for things like captured by the Leviathan). It's possible to replicate this in a mod, but it's a lot of time and effort.
1. Create high poly, detailed models of the characters and/or ships, scenes, objects and props required.
2. Skin the above models.
3. Rig the above models for animations.
4. Set up the animation.
5. Render at a decent quality(not much of a problem if it's just at the same res as the game, they do pretty small animations, a decent quad-core could render a short animation relatively quickly(an 1/2 hour to an hour for 30secs, given pretty decent render settings). If you want a highly detailed HD movie, then it'll take ages.
6. Re-encode to .bik format(horrible format, imo. It'd be better to find a workaround so it plays .avi or MP4, etc)

Ask Silveredge9 how he did it. There are a couple of custom BIKs in the BOS:SR.

What Tangster said makes sense, but I only have half a clue about what hes talking about...

Just to show that it can be done(but is much easier with vehicles) here's one I made earlier.
View here (http://s163.photobucket.com/albums/t308/dudquitter/?action=view&current=Z-Headhuntermovie_01avi.flv)
And a really old Star Trek one.
Here (http://www.veoh.com/browse/videos/category/scifi_and_fantasy/watch/v19598972aRY7bj52#watch%3Dv184932373tdYhDna)

From what I understand, in say the TSL application interior bik can be rendered using cutscenes, there are a few mods converting biks to game rendering for higher visual quality.

But indeed what I'm interested in is exterior space scenes in TSL. A search could not find me any tutorials for this kind of modding, but as you describe it is an entirely independent modelling/animation process which is simply packaged with the game and not as I'd hoped some kind of plug in.

Yet again as you say it is possible and certainly is integral to conversion mods (I haven't installed any but assumed they would have new exterior biks if good quality).

It sounds like a matter of prohibitive skill requirements, I'm no more a programmer than changing a tyre makes someone a mechanic.

no programming involved(except the script to cue the cutscene to play after an event, ie, leaving a planet) The animation just needs to be modelled and rendered.