If you make missions for WoD itself, there is nothing you need to import. Just open up the vp with VP-management tools like VPView, VPMage or MajaExpress and look up the names of the files you want to use.
If you intent to include WoD assets into your own mod, that's a bit more complicated and covered in tutorials over in the FreeSpace Modding forum (and you should ask Spoon for permission before doing so obviously).
As for the voice acting, I have to partially agree and disagree with you. If it's done well, it helps the atmosphere, but if it's done bad, it can ruin a campaign, film or series (just try watching Gundam 00's german version.... that thing is so bad it can give you nightmares. Hard to beliefe anyone got paid money for that abomination! You don't even need to understand german to notice how awfull that VA is.).
That WoD is anime style makes it even harder to voice act, because for me anime screams for japanese voice acting (with subtitles for now, since my japanese isn't yet good enough to watch without them). Add to this that the majority of the main cast are female (with the vast majority of players being male, getting female voice actors is very hard) and you've got yourself an almost, if not completely impossible task.