This morning my mechanic rectified the badly fitted rear strut - the problem was two fold:
1. the spring wasnt seated in the rubber mount, and
2. the rubber mount had rotated in the hat when they torqued the nuts up on top of the strut.
As soon as that was done I had the alignment done again, to realign the rear which is now set to 3mm total toe in (slightly offset to correct an 0.05 degree off caster at the front left - not sure how to deal with that - I'll probably just ignore it, and live with it.)
So, the car is now bolted together, and setup correctly. I've also driven about 1500kms since the billy's were fitted and I can describe the handling AND the ride as ............ superb!
I expect that some of the improvement is down to the setup 'settling', however that badly seated spring must have been causing a few problems because now there are absolutely NO noises anywhere in the car, other than the noises that are MEANT to be there.
On sharp bumps, you get a nice 'thwap', it doesnt throw the car off line and the handling is.. simply amazing.
The ride is firmer.. but i'll say it...
It's more compliant!
And finally.. the crashiness, and skittishness is .. gone! Amen to that.
In all, the best money I've spent on the car so far. and i can now happily say, the car is exactly where i wanted, and hoped it would be.
I couldn't recommend the Eibach / Billy B8 setup enough.
Given how well the car is behaving, I've decided to put a freeze on all Alfa spending, other than general maintenance, as I've now spent thousands on her and frankly, the money would be better spent on a GTA
Trainling arms are good and so are the hub bushes. If I was do do this again I would definitely take Graham's advice and swap the springs and dampers at the same time.. but we live and learn. the car is well good enough as it is! It's only a JTS and it now out handles most other csars on the road.. well, it feels like it does anyway! haha
Thanks for all the replies, advice and encouraging responses - for a while there I was feeling pretty damn dejected... but alls well that ends well and you can't wipe the smile of my face now!