Pratim, I am only your fellow user, but perhaps I can be of some assistance.
Regarding your second test scenario, the flattened copy of the panorama which is saved to your device's camera roll regrettably does not ever contain any EXIF data such as time taken, camera model, or GPS coordinates (in my experience with the Windows Phone version of Photosynth's mobile panorama app).
Regarding your first test scenario, could it be possible that in your iOS settings, you have not given the Photosynth mobile panorama app permission to use your phone's location?
Regarding panoramas which you have uploaded which do not have a location attached, you can manually add one by signing into your account on Photosynth.net on a laptop or desktop computer (Windows or Mac) which has Silverlight installed ( http://microsoft.com/getsilverlight ).
When you visit one of your panoramas' view page under these conditions, you will see an [Edit this Panorama] button below the viewer.