No, I didn't take umbrage on a personal level! (had to look that word up first though, hehe). We've had our little political discussions via Email before and I am glad that I can talk to you about topics like that on such a logical and civilized level (which is not to be taken for granted)!
I see now what you mean with your China argument. I have to confess that I didn't understand it at first. Still the EU and China are quite far apart concerning this blatant intervention. AND I still disagree with you on your supposition that the governments should stay completely out of the picture. Like I said, I am afraid that we might be at a point where the market is already beginning to fail. If there would be no intervention and only one of the two big ones would survive a battle, do you really think that things would improve? The survivor would have no incentive for development at all, and could probably sell overpriced old technology for the next half-century.
On a sidenote: Tarrifs are just like any other governmental intervention: They are not "ultimately bad", but can be a very reasonable tool of economic politics. May I remind you that both Europe and America used tarrifs in many cases to protect various industries while they were still in their infancy? It makes sense now for other countries to do the same thing (see Latin America), until a particular industry is competitive. It's no coincidence that it's always the rich countries who tell everybody what a great thing free trade is! It's not because they want to selflessly share their secret of success, but because they would benefit most from it.
To come back to the subject though: Do you think that airport infrastructure would have to be changed for the A380? I am not sure, but I think that it was built so it can perfectly fit into the parking slots at the gates. Maybe they'd have to use two gates instead of one though, but other than that I don't see the problem. Please elaborate if you know more about this!
Well, I guess it depends on how one views the effects of tarrifs and other forms of subsidization or support. The reason I think that they are ultimately "bad" is that they are a form of artificial price fixing, which in a truely open marketplace is a way to disincentivise on the part of the side being assessed the tarriffs. I do realize that it's in use in many economies, just that it is a band-aid solution and can harm in that the side assessing the tarrif feels protected, and might do less to truly remain competitive by not feeling urgency to improve a product and/or reduce costs of it's production. That's the downside to tarrifs that a truly open market should not accept.
If one major aerospace company went out, then yes, there would be a vaccuum, and the company left would have a monopoly that we would have to deal with the consequences of. It would indeed be counterproductive, and I understand why you feel that subsidies for the sake of keeping something afloat that would otherwise fail can be beneficial to all as a result. Just that it leads to the aforementioned other problems I noted. The best situaiton is to have two, or preferrably more, companies go at it in a truly open, non-subsidized fashion, so prices everywhere could come down, which trickles down, and lets airlines reduce costs, carry more passengers at cheaper prices, which then means that more planes would be needed, and there you go with the upswing side of things once again

As for the infrastructure to support the A380, yes, it has to be changed to accommodate. There are three or four main things that need to be done to airports to support the plane;
1) Runways need to be reinforced due to much greater landing weight. The runway at Heathrow had been modified to handle it, and the test landing was to see the impact of landing the plane on the new surface.
2) Taxiways need to be widened and altered so they don't cut at high angles to accommodate the much greater wheel base of the A380. Reinforcement of the pavent throughout is also a requirement here.
3) Ground handling at the gates needs complete modification. The ramp jetways in use at airports today do not elevate high enough, nor do they extend out long enough to provide for mating to the side of the airframe. The arrangement of such ramp jetways also needs to be modified to allow for multiple areas with those improved jetways to hook up simultaneously to the same plane, meaning a special concourse wing area needs to be constructed specifically to handle the plane.
4) I am not certain on this last point, but I did hear that some specialized ground handling equipment for servicing the ship between flights was also required. The primarly ones here being the conveyor belt baggage loading trucks, galley servicing, waste pumping, and fueling vehicles that may require greater elevation capacity. I believe that most ground handling vehicles, with only a few exceptions, would have problems working the plane. If I find out differently, I'll let you know. I believe the plan is to have three to four gates on a side of the plane for boarding/deplaning.
Even without item #4, the other three make it extremely expensive for an airport to take on that plane. This also begs the question... if you have limited numbers of airports in the USA willing to make the multi-million dollar investment, what do you do for divert airports in case of an emergency? In the USA you have around 60 commercial airports, only 4 of which stated they'd eventually accept the plane, Chicago, New York LaGuardia, Los Angeles, and Atlanta, but they are not really capable of it yet. I'm not sure I'd feel too comfortable if I was traveling along, had an emergency, and was unable to land safely because no suitable airport was nearby.