Congratulations: I think that it is exactly the same colour combination as mine, and the blue is Indigo Blue.
You must be missing the parcel shelf. Jaguar could doubtless supply one (at a price), but I wonder if you could pick one up from a scrapyard. This may not be easy though, because I believe that the stays are easily broken.
The handbook should deal with the pairing of phones. I can't really help there because I rarely have my phone switched on, so have never tried to pair it.
I don't really know what mpg I get. I keep the display set to tell me the range I have left in the tank, which I regard as far more useful information. I don't doubt that I may get as low as 14mpg from a cold start, followed by highly spirited driving, but I think that I probably average something in the low 20s. I did once work out my consumption over a summertime 300 mile round trip on motorways, which worked out at 26mpg.
I don't do a high mileage in the XK, so the mpg is pretty irrelevant to me. Even for those who do a higher mileage, I would suggest that when it comes to calculating the cost of running a car the rate of depreciation can be a more significant factor than the mpg. The rate of depreciation of XKs has tailed off, and I hope that they may even go up in value in years to come.