The TC cannot be partitioned and the store who told you it could are liars.
You can create a disk image..
See Q3 here. http://pondini.org/TM/Time_Capsule.html
It is not hard just labourous.. takes ages.
The TC is an extremely unsafe place to store files.. it has no means to back itself up.. And Time Machine which is the brains is on the computer, it cannot backup network drives.. DO NOT STORE FILES ONLY ON THE TC. One day you will corrupt and lose the lot.
TC is a backup device for Time Machine.
Thanks a lot for your swift reply
Allthough I feel a bit put off by the fact that the store apparently did not know
what they were talking about I still love my TC for its ability to perform backup
in a quite unique way.
So for storage of pictures, video etc. I will go get a "normal" external harddrive.
In your oppinion, is there a "best choice" for such a drive? I think i read somewhere
that it is possible to have an external drive that does not need a power supply but could
only with the USB connector
If your computer has a high power USB port yes, it might work.. it still puts a strain on the computer. Particularly laptops and will drain the battery super fast. So think about it.
You can get a 2.5" drive if you only want a disk up to 1TB. Over that size you need 3.5" disks.
If you have USB3 they are cheapest and best value for money speed wise.. USB2 are much worse than FW800 which is still a good bus but being phased out.. thunderbolt is fastest and will cost you an arm and a leg plus the bits in between.