Have a long hard think about this.
Reading the review of the seagate, the problems with using a wireless device like this are great..
This device is trying to be a network device.. that is the only way you can connect to wireless.. but at the same time, provide some access to the internet.
Wireless on your computers/idevices cannot connect to two wireless AP's at the same time.. That makes the Seagate useless.
Read the review. http://www.pcworld.idg.com.au/review/seagate/wireless_plus_1tb_hard_drive/457705 /
What it is apparently doing is providing a link to your main wireless router.. ie the TC.. so you can have internet at the same time.. but note.. this is extremely slow.. as noted in the review.. the internet speed is really poor due to the lack of proper networking. You are using a box which is effectively a hotspot.. but is linked by wireless to your main router.. If you want a definition of how NOT to use wireless in a network this is it.
Without ethernet connection forget it. To simply have a wireless hotspot to carry around with you.. IMHO there are lower cost and superior ways.. since wireless is not of much use and will be slow.. plug a 2.5" drive directly into your computer. Or use cloud services with a 3G or 4G modem or tether to your phone. Don't forget you can carry around a pretty big store of files now in SD cards.
I also like the idea of being able to take the wireless portable drive wtih me so I can edit photos or view photos from my other laptop on the road.
So you cannot plug the USB drive into the other machine?? Wireless hotspot usage without 3G connection for on road seems to be an expense for not much gain.. but of course if you want it for this great.. just don't expect to put it into the network easily other than by USB. And for that to work I would need to study the specs more closely.. but if you cannot format it HFS+ don't bother. Using iphoto on non-HFS+ drives is not recommended.
If I go with a NAS drive - I can connect that to the TC for connectivity, but then how to incorporate the data on that NAS drive onto the TC as part of the backup.
CCC is $40 software.. it will do whatever you like.
but losing the photos and home videos would be:(
You must be very careful with iphoto library.. and videos more than likely.
iPhoto: Issues with FAT32-formatted drives
iPhoto: Sharing libraries among multiple users
This article states..
It's recommended that you store your iPhoto library on a locally mounted hard drive. Storing your iPhoto library on a network share can lead to poor performance, data corruption, or data loss.
You are playing with fire using the Seagate to edit iphoto library.. and it is important you realise the risk.