I didnt understand much of what the original poster typed but in an effort to help ill offer some advice: Make sure youve downloaded the correct programs or drivers or whatever they are called for your wheel from logitech's website. Using that program (that you got from logitech's site) you can adjust how many degrees of steering the wheel uses to take the car from full lock to full lock (up to the limit of the wheel itself). Also, once you are in live for speed, make sure you set the number of steering degrees you are using to the same number you set the wheel to using the logitech wheel program/manager.
Also, if no matter what you do you find the steering too twitchy. There is an option in live for speed options called wheel turn compensation, (i believe) by turning this up you will get smoother (slower) analogue sensitivity motion towards the center area of your steering which can help keep steering from being too twitchy in the area you need it most.
Hope that helps.