Hey, I'd also be interested to know more about getting detailed debugging info, maybe someone can comment on that... but things I do know that might be helpful:
- You can get a debian 9 template by running: `sudo qubes-dom0-update qubes-template-debian-9` (see docs here: https://www.qubes-os.org/doc/templates/debian/)
- There are some vm logs available at `/var/log/qubes/<vm name>`