"Is it safe to use loads listed for the 44 Special in 44 mag cases?"
Considered to be a bad idea. The difference in case capacity can change the way the powder reacts, even though some loads may overlap in similar cartridges. This is paraphrased on my part, but I did read it out of one of the loading manuals.
Hodgen's web site has reloading information. Find the "Cowboy Action" load tables. Some of the other powder companys have "Cowboy" information as well, but I have used quite a bit out of the Hodgen site.
Accurate Arms XMP 5744 runs a little dirty, but gives you pretty good case density with light loads. Accurate also has an online reloading manual with cowboy loads.