Hi Neil,
Glad you like it. I have the same car and can probably help you with a few of your points.
The left hand steering wheel small black know (when turned) shows all driving data:-
The fuel economy readings have two groups - you will see some are tagged with a red "1" and some with a red "2". The "1" tagged data are readings that relate to your current, in progress or just completed journey - that will be average fuel consumption over the journey, the average speed, the duration. All the average mpg readings have a zero icon with oblique through them. I think journeys where you stop the car and restart the journey within an hour or two act as a continuation of "journey 1", rather than a fresh start journey, if that makes sense!
Whereas the red "2" average mpg reading is an average over a much longer period than one journey - since the last time the mpg data was reset. In my car this is about a thousand miles of data. I think you can reset it by turning the small black wheel and pressing it in and holding it for a second or two.
The car also has instant mpg which you can set to be visible while driving if you are fuel conscious.
As for the phone, you should be able to use the big left and right arrows on the left hand side of the steering wheel to select the phone and then scroll through the contacts using the left hand side little black wheel. Making a call is then as easy as pressing the little black wheel in with you finger when over the contact you want to call. Other ways of calling are using the rocker switches in the footwell just above the large wheel and pressing the switch towards "Tel". You can then see "call" on the MMI screen as an option for one of the selection switches around the large black wheel. The commands/functions in the four corners of the MMI screen correspond with the four switches around the largeMMI wheel. So to make a call is the top right button.
You will soon get used to it. It's just very different from a lot of other cars! Less buttons on the dashboard and more multi-function knobs.
I am a ex-techy too and now cope with it, even though my 6 year old learnt it all before me!
Steve