I don't have a 7100 (I have a beyonwiz) but can perhaps provide a couple of hints.
1. The EPG interface in your PVR is the one provided by your PVR supplier, the only thing ICE does here is provides the data to fill it.
2. For the Beyonwiz, you have to setup a "device" on the ICE webpages, and then on the Beyonwiz, make sure that you point it to that same device that you setup on the ICE site (and of course put your username & password in).
Then once you have done this, you simply, from the ICE widget or Web pages, choose shows you want to record, and after some time, it will upload to your PVR (some time being about no more than once every 30minutes or so).
Of course you can set timers from your Topfield EPG (hit the "REC" key on an EPG entry probably if it is anything like the Topfield 5K and the Beyonwiz). But if you want to use interactive, this is done via the ICE Widget on your PC/Mac, or ICE Webpages (which are also supported on a mobile phone with web access), or Iphone application now too.
Regards