Inbound Action scripts are server-side scripts that run when an email is received by the system. They can use the current object to access the record that is created or updated by the email, and the email object to access the properties and methods of the email message. The previous and event objects are not available in Inbound Action scripts. The producer object is only available in Record Producer scripts, which are used to create records from a service catalog item.
Reference:
Inbound Action scripts
[Record Producer scripts]

The welcome screen appears every time a new application is created through the Guided Application Creator. The welcome screen provides an overview of the steps involved in creating an application, such as defining the app name, scope, and tables, configuring the app user interface, and publishing the app. The other options are not true about the Guided Application Creator. The global scope option is turned off by default, as it is recommended to create applications in their own scope for better security and performance. A scope application user role is not automatically created, as the user can choose to create one or use an existing role for the app access control. Default access controls are not automatically created, as the user can define the read, write, create, and delete permissions for each table in the app. Reference: Guided App Creator

The Application Repository is a central location for storing, managing, and distributing custom applications developed on the Now Platform.
From Developer Site > App Repo:
"The ServiceNow Application Repository stores custom applications and enables developers to distribute applications across multiple instances in their organization."

Administrators can grant non-admin users the ability to develop global applications. Delegated Development is for the scoped applications only Reference:
The incorrect statement about Delegated Development in ServiceNow is that administrators can grant non-admin users the ability to develop global applications. Delegated Development allows administrators to grant non-admin users the ability to develop scoped applications, not global applications. Global applications are accessible by all other applications and do not have a namespace prefix. Scoped applications are isolated from other applications and have a unique namespace identifier. Delegated Development provides more granular control over the developer permissions, application resources, and data access. References: [Advantages of Scoped Applications in ServiceNow], [Product Documentation | ServiceNow]