Sounds like you're looking to deliver an edited master with splits.
You'll need to create a new, custom Sequence with the Mix popup menu set to Multichannel with the Number of Channels pop-up set to 8. Change any existing Audio Tracks to Mono and add more until you have 8 Audio Tracks. You can set the Output Channel Assignments here or in the Audio Track Mixer tab later. Optional: Rename each Track to reflect the mono files that's going to get placed. Renaming Tracks can also be done later in the Audio Track Mixer.
Add your video to Video Track 1. Do not include any linked or merged audio. If you're working in the same project in which you edited the project, this may require copying and pasting from another Sequence.
Add your mono audio files to desired Audio Tracks. This is probably dictated by your delivery specifications, like A1 being Stereo Left, A2 being Stereo Right, A3 being 5.1 Left, A4 being 5.1 Right, etc.
In the Audio Track Mixer tab, double-check or make the Output Channel Assignments (A1 to 1-2, A2, to 1-2, A3 to 3-4, A4 to 3-4, A5 to 5-6, A6 to 5-6, A7 to 7-8 and A8 to 7-8). Then set the L/R panning (Odd tracks to -100 all the way left and even tracks to 100 for all the way R).
You may have to enable the Monitor Channel buttons at the bottom of the Audio Meters panel (depending on your audio hardware) to hear what's outputting to channels 3, 4, 5, 6, 7, and 8.
Play the Sequence and use the Solo buttons to listen to and check one track at a time.
With the Sequence selected, choose File > Export > Media.
In the Export dialog box, set the Format pop-up to something that support multi-channel output like QuickTime. Under the Audio tab, make sure the 1st Stream is set to Mono. Click the plus symbol until you have 8 Streams each set to Mono. The Source Channels column should show each Stream going to its corresponding Channel (Stream 1 should show 1-1, stream 2 should show 2-2, stream 3 should show 3-3, etc.). The Channel Layout should be fine set to Mono. If you're not sure what the delivery specs call for, do a second export with this set to Discrete and be sure to name your two exports so that you can easily tell the difference by the filename.
To check your export, import it back into the project, open it in the Source tab and click the Drag Audio Only button to view the source audio tracks.