remember:
don't enable/activate catalogues which contain unstable apps like testing and devel.
they might cause serious problems and they will use free space on your small rootfs-partition which always causes problems!

you may want to post which catalogues you have activated. (maybe there are some more to deactivate)
and you may want to download the "storageusage" app which shows all installed apps and how much memory they are using. so you may consider to uninstall apps which are using too much rootfs (as they aren't optified yet)