Well, I'm not that familiar with the RCA Pearl, but I took a look at the user manual online.
First, the files that the manual refers to as "secure" are WMA files that have DRM (Digital Rights Management -- the player checks to make sure you have the right to play the file). You aren't going to have much choice with these files -- you'll have to use the recommended software to manage them.
For ordinary MP3 files, you probably don't need any special software at all. Once the player is attached to the computer via the USB plug you should be able to use Windows Explorer to "drag and Drop" files into your player. According to the review at Cnet, <HERE>
it looks like the Pearl doesn't really support playlists, other than an "On the go" playlist, so there really isn't too much to "manage."
Winamp and MediaMonkey both have free versions that should help you transfer files on and off your player. Of the two, I like Winamp better, but others may have different favorites.
But really, with a 2 Gig player you may not need much management. Try opening it with Windows Explorer and see if that works well enough for you.