Star Destroyer with fiber lighting
My first lighting project

Treehugger
An alternative to using fiber glass, could be to use led's, one led to light several window openings, perhaps though a somewhat opaque surface like matte transparent sheet of plastic.

Black Baron
The kit comes with a internal led lighting kit but that is the traditional way I want to avoid. If there is any problem with the lights you would need to open up the model and design it to be opened. I rather put all the electronics outside so the model doesn't need to be touched if lights go out. There are instructions with this kit how to do the fiber lighting and that is basically what I'm paying for. Being shown the process by an expert, so I can apply it elsewhere. Not having to "invent the wheel" on my own.

Starbase101
When I build mine I'll be doing it similar to how ILM did the studio model, with the top section removable for internal access. With proper light-blocking, there will not be any light leakage. I honestly don't see how you'd be able to light everything (all the "windows" and engines) with the light sources outside of the model. Being solid-state components, unless you exceed their current rating LEDs should last indefinitely. Doing a "burn-in" period before permanently installing the lights will reduce the chance of later failures from manufacturing defects, but still a good idea to have "important" lights serviceable in a larger model.