Yes, you can dump files on the ipod in any way you want and play them. I'm not sure what you mean by making it act more like the ipod's firmware. If you mean to browse your music by their id3 tags then you can refer to TagCache in the manual.
Really, Rockbox in general is not all too hard to use. If you were able to successfully install it, you're savvy enough to at least learn to use Rockbox in an efficient manner. When I first used it I was all fussy about what menu did (You mean I have to press left to go up a level!?), but it becomes natural in no-time and when you get back to Apple's fw, THAT'll feel foreign.