CRM integration is an awesome usecase. Thanks for sharing your thoughts here. We will work on the possibilities.
As for CSV import, we already have an option to import subscribers from a CSV file. Under the subscribers tab, click on Add Subscribers > a popup opens > Click on Import subscribers > here you can import a csv file with the format mentioned below (you can also look at the sample csv file format).
# Format: email,subscriber_name,subscriber_emailid,[component1],[component2]
email,Zylker Subscriber_1,email@example.com,Zylker API,Zylker Website
email,Zylker Subscriber_2,firstname.lastname@example.org,Zylker Website
This will import users. In the csv file you can assign components to which you want a user to be subscribed to.
Hope this helps.
Product Manager, Site24x7