Skype supports separate audio output device for ringing - good news. Bad news is I'd forgotten the HP doesn't have any onboard audio. So to achieve the 'always on' ringing I'd need to add a sound card into the spare PCIE slot. Looks like about £26 on
EbuyerSkype hotkeys can only be Ctrl/Alt/Shift + key based, sadly my current remote doesnt support those commands. On advice from the interwebs I've added an infrared keyboard device to the Harmony "Windows Media Center SE" which should be able to send the required keys but for some reason my receiver doesn't respond to it. The receiver is MCE compatible so everything says it should respond. Not how to proceed.
Other than that, got a Logitech Lifecam which does a great job of showing the living room with a decent built in mic so thats a step forward.