1. Unplug the level sensor & bridge the pins. If the flashing stops then you need a new level sensor, if its the early type you can just buy new & swap over, if its a late round tank you need to replace the whole tank! If the flashing continues either the wiring or control relay are dodgy or the dash clocks/temp gauge is shafted.
2. Will be a vac leak at the vacuum tube from the brake servo hose to the right of the inlet manifold, usually its caused by the vacuum hose being disconnected from the back of the dash clocks.
3. Another thing to check is the front camber, my passenger wheel had lots of positive camber (stuck out at the top) which resulted in the wheel being off centre and a dodgy steering feel. Once I fixed it the wheel was straight again and all was well. Are the front tires at the same pressure and the same make, and make sure the rack is centred properly!
TBH I'd replace all the track rod ends, top mounts & bushes on all 4 corners and see if that helps. If the back end is still doddgy then its most likly the bushes that are shot! Its a strange feeling indeed, like the back is seperate from the rest of the car, feels like it kind of catches up with you when you go through chicanes 'swiftly'
