It is the property used to define the Editions that the package provides.
No. You do not have to use the auto loader to use editions.
Editions can be considered in the following parts:
editions property inside your
package.json file used for defining the editions a package provides
This standardised property can then be utilised by optional things due to its standardisation, such as an auto loader that can automatically include the correct edition for the current runtime, or renderers that render the available editions for the consumers awareness. These latter parts are entirely optional, and should not detract or distract from the promotion of the valuable by itself
Yes, but they are all terrible, hence why editions exists.
You can set the environment variable
yes, this will output to stderr the relevant failure and stack trace for why editions are failing to load.