I think one aspect of geometry that is really important that most companies totally ingnore is allowable tire clearances (w/ and w/o fenders). That gets asked a lot on bikeforums.
You would need to use a real database type setup, wiki is crap for databases.
Sorry, most manufacturers do give full specs on their websites.
not really (see above) and its nice to have it all avaible on one pages, especially for cross-comapny comparisons.