I spend a few days doing it. Between limited docs, support and hacking I kind of got everything to work. Even kind of sort of passed the wife test. If anybody needs any XML help, ask. I will try to answer if I can. I'm far from expert in that stuff but I got my stuff to work.

Is it possible to remove items or entire menus from individual devices? For example, one of the menus for my CD Changer is titled "Group Mode" and I'd just as soon it dissappear since I don't use it. I selected the option "Modify the XML for this CD Jukebox" but there wasn't much there. I gather the basic character of any device is "inherited" from the "Language ID"? Maybe I could create a new device from scratch, or is that even possible?

David

A function key "activity" can be changed:

Click "More Options" in the "Activities" pane on the main Remote Configuration menu.
Click "Change the settings for an activity"
Click the activity you wish to change, e.g. "Change Button Function" or "Key ChanDown NavMode"
Now just walk through the setup just like you did when you programmed the key the first time.

David

It is possible to remove entire menus from individual devices. In fact, once you touch a device menu, you will overwrite all existing menus. It's a downside, of course, since you have to recreate everything, even if you need to add only one item. Harmony's support wrote that there is a way to add to an existing device menu but so far he didn't provide a way to do it.