That merely shows the longitudinal and lateral components of the force exerted on the tarmac by the tire. It already takes the angle of the tire and its direction of drive into account.
Do you honestly think these things through before posting threads about them?
Well, you're understeering there and that's what happens when your front tires loose grip. Just because your tires start to slide doesn't mean they have no grip at all, it's just lower and therefore you understeer.
That car is XFG, right? What gear are you in when you floor the throttle? I think I'd expect a car to understeer a bit more, but if you have an open diff, all the acceleration force would go to the unloaded wheel so it wouldn't cause much understeer.
What's the point of these threads anyway when we know that there is a brand new tire physics engine under way?
I cannot check it right now, but default race S setups always seemed kind of easy to drive to me. It uses clutch pack diff, right? What's the locking ratio under power on that set?
Anyway, the video you uploaded doesn't contain any real info that can be used to draw some conclusions, we don't know vehicles speed and the power engine is sending to the wheels.
By the looks of it you are applying power, so the car is effectively dragging itself around the corner, despite the excessive steering angle. Also, the rear tyres are cold, so liable to increase the oversteer tendency of the car.
Not very unrealistic if you ask me, but the video was a bit rubbish to tell exactly what you meant.
Then you guess wrong. I have a personal experience with understeering in a real FWD car (who doesn't?) but I still fail to see what's so utterly wrong with the behavior you're complaining about. You should take into consideration that these are slick tyres we're talking about here which I think don't loose grip as abruptly as grooved road tyres.