Additional experience, include Windows in virtual machine
I've been experimenting with all these suggestions. It appears to me that the key functionality is application dependent. For example, in Mail I find that the Command key plus arrows does the trick. Ditto for Pages (word processor in iWorks). But neither the Function or Command key do anything in Numbers (the spreadsheet application in iWorks). In Safari both the Function key and Command keys with arrows can be used to navigate a website page.
I have to run certain Windows applications. I've installed Parallels Desktop and Windows 7 + Microsoft Excel and Word. In Excel the Function key with left and right arrows seems to move to left and right ends. The Function key with up and down moves "a whole bunch" but not to the top or bottom. At least there is SOME functionality! Similar experience with Word. The Command key with arrows will do something, but nothing related to cursor movements.
I'm not surprised that I would have challenges using a Mac keyboard in Windows 7 environment. [I wonder what would happen if I plug in my PC keyboard to the Mac?] But I am surprised to find inconsistencies in the Apple applications.