My 166's front tyres were also ridiculously worn on the inside edge. And funnily enough, I had Goodyear Eagles fitted as replacements, as well.
Inside edge wear in my opinion comes solely from toe-out. My 164, due to aged suspension, has 3 degrees negative camber on its front wheels and it doesn't seem to affect the tyre wear.
I had a wheel alignment done to the correct spec. but it still feels 'odd' to me, nowhere near as stable as my 164. I suggest that the 166 wheel alignment specs are WRONG and the 1.8mm toe-out each side is not required - I reckon they should be set parallel. But then, compared with Alfa Romeo, what would I know?
-Alex