Quote: "But one question: can a custom gun in fpsc have a texture for an arm and a gun? If it can; How do you get it to work?"
Yep, sure it can. THat's what Modpak 5 uses.
Quote: "And is it easy to import animations into fpsc?"
Well, that depends on how well you understand animation and gunspecs.
I'd say your first time will be frustrating. But thats the case with anything.
I'd highly reccomend reading FredP's Milkshape tutorial. (just open fred's profile and search his posts), as well has getting manofart's tut on milkshape animation exporter. Search "wizard" to get a post by manofart, then get all his posts by opening his profile, THere's one call Milkshape export or something.
Other than that, there's not much more to say. Initally, I'd just copy the COlt45 folder, replace the HUD with your mesh, and work from there.
Peace