General questions and answers
Yes, you can use DM Editor as a separate product and it's open source.
In most cases yes, you need you server to build frontend. The server can be in Nodejs, or other platform like PHP/.NET/JAVA.
For small sites you can use website service without any server, which is a product we corporate with our partner.
You. You have all the right to your data. For instance, you can always ask for exporting data from us.
No. It can be used in any solution, as long as you have content need - editorial work & frontend display, maybe permission control. For instance, CRM solution may have content to publish, mobile app has a content section.