I had a mini -pre MOT- service done which included a 4 wheel laser alignment (I know the rears are fixed ). Since then the steering is noticeably lighter - quite disconcertingly so - was the car's previous apparent stability and desire to go 'forwards' the result of a large toe-in? Handling-wise it feels spot-on now, but it never felt bad before.

I don't think that the "rears" can be fixed, its only the position of the rear wheels wrt the front wheels by moving the crossmember left or right a bit - ie moving the fronts side to side, the (front) camber and toe'ng that gets sorted. Without sounding nasty - tyre pressures?