iMac, Time Capsule & External HDD - what would you do?

I have:

iMac (750Gb)
External Drive from OWC (750 Gb) and
Time Capsule (500Gb)
Dell Laptop (work machine)
WD 320 Gb backup drive for the Dell laptop

My Data on the iMac is only about 180GB - I am adding stuff, mostly movies, about 1Gb per week or so.

My OWC drive was dedicated to backups - Time Machine partition and also Super Duper and CCC partitions

I tried the Time Capsule for Time Machine backups - works OK but I'm doing it via wifi so it can be slow when I add media to the iMac.

My question is - should I keep the OWC as my Backup drive and use the Time Capsule drive for something else? I have about 60Gb of music on the iMac, which I thought I might put on the TC drive as a NAS that both the iMac and Dell could access.

Overkill on all the storage, I think - wondering how to best use it all?

I'm sticking to my external drives for backup (have one for each Mac), and are only using the Time Capsule as a file server (and it does a great job at it).

And I don't like Time Machine, it's got to few options... so I stick with iBackup still.

All I need now, is to find a good routine for making backups of my Time Capsule