RE: Importing Expense Reports
In the help center you can refer to this section : ‘Account Setup : Data Management : Guidelines for CSV Import Files : Supported Record Types for CSV Import’ to get a list of all supported records for CSV imports.
Expense Report is indeed not available at this time.
It can be scripted though so there are ways to import it. Basically you’d need to create a custom record replicating the information to set on the Expense Report. You would then need to create an user event script deployed on that custom record that would take the information and use it to create the actual Expense Report. You would then import your CSV into the custom record and the Expense Reports would be created.