1) yer

2) no. your laptop's CD-R wouldn't work because it can't record music on the fly. to burn a proper cd with that, most software needs to know how long your cd will be (ie what tracks, the toc, etc). a stand-alone cd burner would work for this but that's really not the ideal solution either. the majority of DJs record their mixes by using a couple of turntables and a mixer.

3) it's small and compact basically; it's a decent mixer that gets the job done. if you use a laptop, you can mix your computer's sound out of one channel and the dmp-555 out of the other for live sound applications. you can also mix two tracks simultaneously (albeit cumbersome compared to the traditional setup) using the 555 so you may not need the laptop at all.

there are also software programs that will let you do what the 555 does without the hardware, right on your computer. if all you want to do is make mixes and never DJ to a crowd (read your basement's wall to some), this is a better solution, however I love the hands-on approach of real gear.

Just to clarify...

2) I used to use a program called "Spin Doctor" by Adaptec, but I don't know if it's still around, which would allow you to "record live" to a CDR drive. It would max out at 74 mins (or 80 mins).

3) Dave's post may be a bit misleading - if you're using the DMP as a controller, you'll probably want 2 soundcards (or one with multiple outs), and it's more "user friendly" to have an external mixer, although it's not necessary. If you're using the DMP as a player, you don't need the PC (or laptop) at all, the audio comes directly from the device. Just remember - no audio comes in or out of the 555 when you're in controller mode.