Everytwin i have ever built or flown has had 0 degrees side thrust on the left engine(s) and 1 or 2 degrees right thrust in the right engine(s).

You will never be able to get rid of P-factor in the design of a propeller propelled plane, its just not possible (until you go to jets). The only way to limit and counter-act P-factor is by learning to use the rudder, that stick still moves once the throttle gets to full!