Sorry for having taken so long to reply, have been away for a while.
Anyway here goes in answer to your questions.....
1. I have tried putting the front wheels to the back, well at least the garage told me they did it and I pretty much had the same problem, vibration in the steering. I have to say though that it feels like the whole car is shuddering, my phone shudders with the satnav on it attached to the window.
2. Tony, it was full geometry I was told. It is a place called Caledonia Wheel Alignment in Glasgow. Unfortunately the computer wasnt working so I couldnt get a print out but the measured the ride height and had all the lasers out and it all appeared hunky dory.
Both balancing and the alignment made it slightly better, at least I hope that wasnt just me thinking it was made better. I am at the end of my tether, I love the car but seriously considering punting it as it just feels so unsafe at at 75 plus mph.
Someone has suggested it might be the tyres, I am ashamed to say they are budget tyres which I have never changed since I got it. Also when I took it for the balancing I asked the guy doing it to check for buckles and he said he couldnt find any.
If I cant fix it soon I am afraid its gonna have to go!