I've just been looking through the Live Object Model reference, and it seems there is no property documented in it to retrieve a clip's tempo. Is this just an omission, or is there really no way to access this parameter?
Anything that shows up in response to a getinfo message that's NOT listed on the refpage for the Live Object Model is an error that ought to be corrected. We already know about playing_position. If you find any more, let us know by all means.