I am afraid the Denon DJ mixer is not the most suitable for recording multiple devices. Especially if you want the recording to be multitrack so you can edit individual tracks later and even overdub the bits you aren’t to happy about.
If all you want to do is record a master output, you could consider something like a Yamaha AG-06 USB-mixer.
Depending on your budget another option is just getting a bigger multichannel USB soundcard (Focusrite for example) that you can hook everything up to. You should now be able to record multitrack into your DAW software (Pro Logic in your case). You should also be able to play back your tracks you made in PL while recording the other tracks (bass, TB303).
You have moved quite a bit away from “regular” Digital DJ setup and into producer territory. To get all this to work properly and know what to do/set, you’ll be looking at getting some sound engineering knowledge. Plenty around the net, but outside the scope of this forum.
So summarizing, Pro Logic should let you record multiple tracks at once, provided you have a way to input everything. A multichannel sound card would work here, be ready for some serious money though. You’ll be looking at around 300 euro or more. You will have enough line/instrument/mic channels to attach everything and record everything to a separate track.
.
