Unfortunately, the Drupal variables table doesn't provide any distinction between variables used for configuration (e.g., whether anonymous pages should be cached) and variables used to store transient values (e.g., date cron was last run, which tabs are currently active in the UI), so there's no automatic way to do this. (Fortunately, it looks like Drupal ...
Many modules store their settings in variables, that's what Strongarm is good for : it can help you export those variables with features.
My usual way of finding out which variable to export (and exporting it) :
see the source HTML of the form where you set the values
in the "name" attribute you will most often find the name of the variable
use drush vget *...
A Drupal 7 database contains various structural configuration. Some of these are:
Entity bundles, e.g. node types or taxonomy vocabularies.
Field bases: These are definitions of fields that apply across bundles and entity types, wherever the same field is used.
Field instances: These describe how a field is used for a specific entity bundle.
Field display ...
Change interface lang to the node target lang
The configuration you describe will always only allow one language when creating new nodes: the current language of the interface.
That is because you have Set custom language as default for new content. (and the current one as the default).
If you want to create content in other languages, you have to visit ...
Gonna go out on a limb and guess that they come from the Node and Comments Form Module, which uses nfs as a prefix for variables.
Failing that, have a look through your contributed modules and see what you have that can be shortened to NFS - that's probably the culprit.
You can do this with Features:
Enable Strongarm module
Create new feature
Export and Deploy Panelizer settings
Alternatively you can do this with a custom module. See https://www.phase2technology.com/blog/exporting-panelizer-defaults-to-code/
It is the vertical tab that is "active" when the node edit form loads. Export as needed (I usually don't).
FWIW, i used 'drush vget' to take a look at the variables value and that made it pretty easy to figure out its purpose. (Drush)