Can someone refer me to a quick list of these specifications, or tell me ... (1) what's the maximum number of fields I can have in a FileMaker Pro 5 database file; (2) what's the maximum number of records I can have in the same; (3) and lastly, what's the maximum physical file size of the same. Thanks.

Maximum file size is 2GB. There doesn't appear to be a maximum number of fields/records/layouts. (In fact, for layouts, the help file specifically states that "You can have as many layouts for each file as disk space or maximum file size allows.")

Of course, if you create related files and link any graphics brought into container fields, it's very difficult to reach that 2GB limit.