The tax incentives to keep the production in the state of washington were to bring the state into line with other states and are available to anyone participating in aircaft production in the state of washington, including any work Airbus might choose to do there. Sooooo, If the EU governments are willing to give boeing 1/3 the developement costs on the same basis that they gave to airbus then I have no problems.
Well, the likelyhood of Airbus wanting to produce in Washington is as likely as Boeing wanting to produce in Southwest France, so this is a moot point.
But, development aid from EU governments
is available to everyone, as the example of the Welsh Development Agency providing support to GE's BA maintenance facility in Wales shows.
As for the rest of your argument......if the "BOEING" part of the airframe is subsidy free and the remainder not, how do we judge the airframe as a whole?