Ah, if it's the entire dictionary and not filtered by the clients to just those fields, then presumably additional data may be shoved in—specifically the trackers to contact.
No, look at the content of the dictionary: trackers are not part of the "info" dict, so you can add all the trackers you want, it won't change the identity of the torrent. Identity is defined by the infohash.
http://bittorrent.org/beps/bep_0003.html#info-dictionary
There are some things, beyond the content of the file, that will change the hash:
- Path of the file (nature_documentary.avi vs root/nature_documentary.avi)
- Name of the file (nature_documentary.avi vs nature_doc.avi)
- The pieces length