You can add 10 more inputs to the 002's... 8 via the ADAT lightpipe (TOSLINK), and 2 via the S/PDIF inputs. Be aware that the maximum sample rate you can record with all 18 channels is 48k.
From what I've seen the firepod does not have ADAT, therefore, you can't use all 8 of its channels to expand the inputs on your 002R as the 002R does not support channel expansion using firewire. You could expand 2 channels using the firepod's S/PDIF output.
Sending the firepod through the 002R 1/4" would work but is not exactly desireable either since you will be doing 2 A/D and D/A conversions on those channels which will likely decrease the quality of your tracks somewhat.
Hope this helps.
---
c