1. Read the whole nightly threads, there are ubuntu and debian repos,
2. 8.02 is the latest official release
3. see 2.
4. if it is ready to release
The nightly builds are in general not less stable than the release version, indeed there are bugs in the release that are fixed in the nightlies.
You can download a full changelog (up to the current nightly) from my server (see signature).