Hi, folks! I wanted to chime in on this, as I love the FFG Star Wars mechanics, and I'd love to run a Lovecraftian adventure in the Star Wars universe. it's something I've been planning to do myself.
One thought is that I'd love to run Masks of Nyarlathotep, but set it in the Star Wars universe. The various destinations in the campaign would be different planets, thematically similar to their use in the adventure. So, London could be Coruscant, Kenya could be a frontier world, like Tatooine, etc.
The other campaign idea would be to have the players be the crew of an Imperial ship sent into the Unknown Regions to scout out something or another (or to track down a lost expedition). The Unknown Regions is a great setting for horror, since it's so far off the beaten path and away from the civilized galaxy as everyone knows it. There are also lots of creepy critters out there that are great stand-ins for Mythos monsters. The Mythos was a big influence on the authors of The Unknown Regions supplement for the D20 Star Wars RPG, and it's a great book worth picking up for anyone interested in this kind of mashup.
I'm still not sure how to handle the Force. It will work as normal, of course. But I'm not sure whether to somehow make it linked to the Mythos in some way, or to make it just another irrelevant bit of mortal nonsense the the Mythos entities care nothing about. My inkling on this that to truly get the Lovecraftian nihilism, you'd need to treat Jedi and Sith as basically more ants out there doing ant things. In other words, the Jedi and Sith think what they do matters, but it's no more important than the fact that human beings on our earth have the bomb or have landed on the Moon. However, maybe their power does link to the Mythos in some way. I could see the Daughter, the Son, and the Father from the Mortis trilogy of Clone Wars episodes being somehow Mythos entities (or avatars of them). In this scenario, the Jedi and Sith are mere pawns of the Old Ones. Or maybe there are factions of each that are trying to suppress certain gods and/or make deals with other gods.
I've also been toying with a Sanity mechanic that works something like Morality. If folks are interested, I can post up my notes on it. In this style game, Morality, Duty, and Obligation would all be available, but ALL characters would have to take Sanity, as well.
I think this could be great fun with the right group. Or maybe I'm insane already?