You could use debian testing. It’s a somewhat “rolling-release” model. You will get more up to date packages with more stability too.
You could also use unstable, but I wouldn’t recommend it personally.
Edit: if you really need the most up to date version of some packages, you can pin them to use the unstable repo. This would be a pretty reasonable solution.
In Linux, the root of the filesystem is /
The command would remove recursively every file/directory in the filesystem, essentially nuking the whole system.