Importing / Exporting multiple layers

Greetings, I need to export / import current document with multiple layers. I tried to figure how to do with sdk documentation and samples, but I can't get the point.



Here's my questions:

1) Can I create, modify, delete layers dynamically in import / export plugins(or file format plugins)?

I've searched the forum and someone said it can be done only in Automation plugin module. Can I do it in im/export plugins?



2) If I can do 1), which plugin type and suite interface I need to choose?



3) If there is any good sample to do something like what I want to do, please let me know.



Any answer and advice would be very grateful. Thanks in advance!