Xoutpost.com - Newbie Question sat nav retrofit help!

Hi there, I'm new to the X5, just bought my first X5 last week.
I've always been a BM man, but a new baby has forced me from my e36 M3 evo cab to a more sensible set of wheels!

The car is an e53 3.0d sport registered on a 51 plate.

Now the story begins here, I bought the car last week for £5250, its in great nick and its just had an inspection 2 and new auto box in 2006, only problem is its got no screen. I paid so little for the car, I figured its worth spending some money on the screen retrofit.

I used to run a car audio installation business several years ago, now I work on the Airbus A380 as a certifying engineer, so this shouldn't be beyond me.

However, I have the follwoing questions:
I have purchased a 16:9 widescreen and a MK4 nav computer. I also have a comprehensive set of instructions for this retrofit.
1. The instructions detail the fitment of the radio module as including the fitment of 2x coaxial cables, (one aerial plus one I believe is diversity). Having looked at various BM52 and BM54, I can only see that the BM52 module has 2 coax connectors, if I buy a BM54, what happens to the second smaller coax lead, do I just not connect it?

2. Second question is, if I leave the samll coax lead unconnected, where do I stand with the famous aerial amplifier, do I need to replace it or not?

3. CD changer fitment is not listed in the instructions. My existing changer has 2 plugs, one power (3 pin, which I will connect somewhere to live/earth/ign live) and another white plug (with 3 white cables with coloured tracers which I assume to be audio). Do I simply plug this straight into the radio module from the cd changer?
I have searched high and low to find the answer to these questions, but cannot find the answer I need, I would be very grateful if somebody who has had experience of this can advise me of what to do.