I keep a serpent star for left over meatier bits. You can also keep the other stars and non pointed spine urchins..etc. I also have a large population of bristle worms that seem to keep the tank clean. Ive never had a problem with them. Anything that is a shrimp or a crab (non-hermit) will be eaten as soon as it drops in the water.
One thing I would recommend and wish I did would be to ensure you have absolutely no bubble algae or aptasia prior to adding cuttles. For natural predators that eat these will be eaten by cuttlefish.
No aiptasia, but my one piece of LR has one bubble on it so I will make sure I get that off, or just not use that piece.
I don't want to rush, but since cuttles seem to be hard to come by, if I get the chance to get 2 female cuttles say in 2 months or so after the tank is set up would they be fine? Or should I wait the 3 months no matter what? I am going to have a 10g fuge with a DSB and chaeto, and my sump which will have chaeto. My LR is comming from an established tank in my house. I also have plenty of LS to seed my new sugar-sized aragonite. I have sponges also that are loaded with bacteria that I used for my QT if that would help any? I will also have a CuC ready from my 55g.
It's best to let the tank get through it's full cycle so you don't stress the cuttles more than they have to be after shipping. Thales, Paradox, and myself will probably provide a steady supply of cuttles to anybody interested.