No. If your disk space exceeds the allocated limit for an existing plan, then you may need to upgrade to a higher plan to get more disk space.
For more details see Plans and Pricing
You can upload any file type like .doc, .xls, .xlsx, .docx, .doc, .pdf, .pps, .ppt, .jpeg, *.zip, *.mpeg. In addition, you can also upload video files into the documents area.
To import documents from Google Docs :
If you upload a file with a different name or file type a warning message "Filename mismatch" gets displayed.