Hi there
I can tell you now the mis-match on tyres front and year is causing your issues mainly.
First of Vreds are better in sub 5c temperatures compared to F1's and considerably better around freezing and sub zero, but saying that you should not be getting these issues.
The other issue is a set of F1's can take serious time to run in even when decent dry conditions, say 300-500 miles, I'd suggest you find some empty roads, turn off TC and completely light the rear end up just in case they are having bedding in issues.
Secondly have you checked all your tyre pressures?
Also the other issue, on the front of your car you have a tyre with reasonably stiff sidewalls and on the rear you have a tyre with soft sidewalls.
Whilst your running different tyres front and rear the car will never handle as it should it to its true abilities.