This is not correct. Movie files do not need to be executable, and never should be! Not that movie files being executable will cause problems, but it’s possible to imagine a scenario where an attacker could exploit it, especially if the files are owned by root. Extremely unlikely, but I work in IT and always think about security :)
You might be thinking of directories, which do need the executable permission to let a user/group/all be able to read its contents.
If you want to make your playbooks/roles more universal, there’s a generic package module which will figure out what package manager to use based on the detected OS.
Or, if that doesn’t fit your needs, you can add conditions to tasks (or blocks of tasks), like
when: ansible_os_family == "Debian"
and use that for tasks specific to a given Linux distro/family.
Ansible will detect a lot of info about each host and make it available as facts. See for example https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_vars_facts.html
No, you give the AIO container access to your docker daemon and it will create / handle / supervise all the other containers nextcloud needs.
You should remove the executable permission, see my other reply. Movie files should never be executable, but directories should be.
chmod -R -x+X *should do the trick, that will remove the executable permission on all files, and set it on directories.