Recently active topics in Wuala tagged with file maintenance

I started this just to clear a few things out. I like to control the size of my Wuala folder and the amount of traffic that Wuala generates but currently I don't understand any of them.

I'm a bit confused about what happens when I drag a file into wuala. This is what I think that happens:
- the file is copied into cache
- the file is uploaded
- the file can be removed from the cache if I click the 'clear cache' button
Wuala also remembers the file location and modification date, so if I want to access a file that isn't in cache but it's still at its original location, I don't need to re-download it.

So, I have a few of questions. First: who maintains my files? I thought that the files were maintained by the Wuala server but the 'Show Maintenance' button in the uploads window still shows some files that are maintained by me.
Second, how can I maintain files if I have no local backup of them?Are they only maintained if I have them in cache?
Third, why does my Wuala folder have 300 MB if I just cleared the cache?

And finally, is that anonymous maintenance stuff coming or what? :)

Thanks