Did you check the pressure if the pressure is too high in the tyres this could have caused the uneven wear with more wear towards the middle.

This sounds all too familiar my last two Alfa's have suffered the same problem, both wearing pzero's both on 19's

My current Spider only lasted 4000 miles before needing new tyres which was unacceptable so i had a long battle with Alfa UK and then Alfa Italy who both said that this was normal wear and tear after many phone calls (at my expense) they agreed to pay for two new front tyres but would not admit there was a fault and they would not agree to have the tracking adjusted to +0 toe in (they are set up toe out) 
so i said that if the next set only lasted 4000 miles i would be asking them to replace them again luckily this set has lasted 12000 mls which i think is reasonable for a soft compound, heavy car on 19's.

Id suggest that anyone who doesnt drive their car like they stole it and wants to prolong their front tyre life to get the tracking set at +0 toe out (or parallel) at  a good tyre place, If you do find the handling compromised you can always get it returned to factory settings 

I had my front tyres replaced at the 1st service and l'd only done 9000 miles
got told by the bloke at Autoworld that cos they such low profile tyres they scrubbed quicker......think he thought l'd just fell out of the christmas tree!!!!!!!!!!!

I think that this type of tyre wear is just due to a bit of negative camber and hard cornering. Nothing to worry about really.

My Pzero's are very noisey when cold once they warm up they do tend to be a lot quieter