Those two are my main suspects, yeah, coupled with that U turn which often surprised me how deep I could cut it without penalty. I'm probably doing something wrong/badly on at least one of them.
K man I'll try my best to explain.....
First Hairpin - you want to cut the corner on the right hand side approach and aim for the apex at the top of the hill (generally I'm in 6th up to cutting the corners, drop to 4th as you reach the apex and break really hard) the Aston should drift a little but keep the power down and you should get round. I've been using the sign on the left at the exit of the hairpin to see if I am doing well, usually if your around 115 mph as you exit the hairpin you should be good down the back straight.
Another marker is the bump in the road, you want to be around 145 mph and then shift up to 5th.
Chicane - is tricky too, basically just go as fast (usually about 170 mph) as you can cutting loads of the verge on the right and then flicking the car left (you'll want to cut a little of the verge on the left but not too much you will defo get a penalty here) without applying any accelerator or break. once you get the turn you'll get it nearly every time.
The following right hander is tricky too again cut the corner on the left and flick the car right while dropping 1 gear, you should get very close to the wall on the right but power it through and as long as you don't get too close (you may get a penalty) then your good.
The "u-turn" is good - you can cut that loads, but try and keep the revs high (press the accelerator on and off to minimise wheels spin) - again try and keep it at around 40mph here.
The last turn - I use the penultimate telephone pole on the left as the breaking point, really hard breaking and down to 2nd gear on and off the throttle as much as you can be while not drifting and then flat out all the way down the straight
Let me know if any of that makes any sense? we could do a pvt lobby later if you want me to show you man?