Indd file, supported by iPad Pages?

No. I think you need Adobe InDesign for that.

What pages can open is spelled out here:

http://support.apple.com/kb/HT4065

No, it is a proprietary format used by Adobe's InDesign. It can only be read by InDesign. InDesign is a cross platform tool available for Windows and Mac. It is not currently available for iOS, Blackberry, Android, WebOS, or any other mobile OS. Hopefully in the future, Adobe will release their Creative Suite products for the iPad...