my tuner also mentioned that Ethanol absorbing water (which can reduce detonation) will also loosen crap in your tank, and ethanol being an alcohol will clean crap from everywhere.
If it gets past your filter, it will clog injectors,and cause your car to run lean because the ECU thinks the injectors are working ok, but it fact they are blocked, causing leaning, and causing detonation.
So its not really the E10 that kills cars..
He said that if you do switch to E10 (which is not a bad option when its available evrywhere) you should change your fuel filter every 3-4 weeks for a few months to make sure your system being cleaned by ethanol is being filtered properly.
He said ethanol is great to tune to, as its resistant to detonation to a small extent, and can have a fair amount of extra timing advance put in (he's seen 5 - 10 degrees in some cases)
Don't take my tuners words as gospel, its just what he's experienced while using it.