A module declares the route:

What is the layout handle of the storefront path /custom/feature/?

You are working on a new entity called vendor. You implemented the model, resource model and collection.
You want to ensure that standard model events will be fired for your model, so an observer can be created for the events vendor_save_after, vendor_save_commit_after and others.
How do you do that?

How do you persist an entity to the database?

A module MyModule needs to send notifications to customers only when the account was modified from a mobile app using the REST web APIs.
You decided to implement an observer for customer_save_after_data_object event.
In which file do you declare the observer?

You are developing a module MyCompany_StoreInfo to display information about brick and mortar stores on a frontend page. The displayed information varies based on the country of a given store.
What two elements automatically render their children? (Choose two.)