I don't know how easy they are supposed to be, but they are reportedly EASIER to keep than most of the other Linckia species, maybe only because they are generally smaller than most of the other species in the genus. I kept a small one (with only five arms) in my 55 for over a year until I moved the tank. He didn't grow a lot, but he didn't die either. From what I can read, they mainly feed on biofilms, but may graze on other tiny organisms. I also read a report of L. laevigata feeding on dying coral tissue, so that might also apply to L. multifora. The likelihood of keeping them successfully probably increases with tank size and "grazing" area, and apparently with tank maturity as well, although my tank wasn't very mature when I threw mine in there.
Unless it's a different species, I believe the correct name is "Linckia multifora" rather than "Linkia multiflora?" Greenbean should be able to correct me if I'm wrong.
(Disclaimer: above post written by a snail guy, not an echinoderm guy)
Cheers,
Don