TV: I don't know if I'm missing something, or if your are, but once you log in, go here:
[Link: harmonyremote.tzo.com]There are two choices down near the bottom: Customizing a Device Menu, and Customizing an Activity Menu. Both of them have lots of good examples.
Then, go back to your HomePage and pick either a Device or an Activity, depending on what you want to change (for example, pick Device for TV if you want to change the channel lineup using XML). There will be a list for you, one of which says: "modify the XML for a device".
... Mike