I think we can say that the downfall of the British, French, Belgian, and Dutch empires over time will generate a lot of OTL's trade, but perhaps later in some cases, perhaps sooner in others. China of course will be a huge mess in the long term, as will Japan. The USSR would actually be less of one, as due to the losses from WW2 the never recovered their rate of pre-1941 growth after the war, and would likely have filled the role that it was with Germany now: as a energy supplier and buyer of its technical exports, probably on a barter agreement.
Actually, without WW2 I would lay good odds on the French being able to retain most of their Empire - Algeria is rather likely to achieve independence and Vietnam somewhat less so, but still likely. The rest, however, I can see staying in some sort of close political and economic union with France. The Dutch have reasonable odds of retaining their empire, Belgium... Yes, probably they'd lose the Congo (get rid of it, more likely, as they can't get away with the monstrous practices they used to strip wealth from the colony any more).
I think Italy has a pretty good shot at maintaining control over its empire, similarly with Spain and Portugal.
The problem for the USSR, as I touched on, is autarky. By the end of the 70s, the USSR was running out of easily accessible coal and oil. As a result, they were pouring vast amounts of resources into developing Siberian resources. I think a complete collapse of the USSR is unlikely (no WW2 means more competent managers surviving into the 80s!) But certainly the Soviet system is going to face a crisis at some point between 1970 and 1990.
As for a POD, let's say Hitler dies of natural causes after Anschluss, so Goering takes over after a power struggle and has to delegate some of the powers of the office of Führer and cannot continue on with Hitler's war plans. Instead Germany is forced to contend with their economic issues as Goering is less politically stable than Hitler and he dramatically tones down military spending to shore up its export markets. No more foreign adventures after the end of the Spanish Civil War. Maybe Hjalmar Schacht comes back and sets trade policy. The point is that trade takes over from military expansion and foreign adventures and the 'Grossraumoekonomie' is set up in the Balkans, while trade deals are worked out with the Soviets and maintained with Poland, plus of course the Spanish and Latin American deals, but trade with China drops off was China loses its ports to Japan.
Germany toning down its military spending after Anschluss means economic collapse - which is massively preferably to WW2 for Germany, but still has a good shot at ending the Nazi regime.
I agree that there will be more trade and German influence in Eastern Europe and the Balkans, in the long run.
I don't think that trade between Germany and South America will ever be on the same level as trade between Germany and Eastern Europe.
Also, in a scenario like this, you may see a sort of German colonial empire forming as Germany supports anti-colonial movements in hostile empires and, where those movements are successful, end up maintaining German-aligned regimes similar to cold war client states.
I wonder whether if Germany isn't a threat in Europe whether the Europeans would join in with the US to embargo her and force her to back down under threat of military force from all the major navies of the world.
If Germany isn't a threat, I don't see why the other powers would unite against her.
We may see a cold war situation develop on the continent if people got particularly paranoid, but I can't see more than that happening.
In that case China then opens back up to world trade and the world benefits, while Japan avoids complete economic isolation and a ruinous war, but doesn't really get modernized during US occupation.
The rise of China
as we know it is highly unlikely in a TL without WW2. In OTL, China was assisted by massive technology transfer from the Soviet Union to China which would not happen without a Communist victory after the civil war and then followed by a smaller, but still significant transfer from the USA to China which would not happen without the Cold War. As such, in a TL with a Sino-Japanese war but without WW2 and a Cold War, China is likely to have a much slower rise.
Also, if Japan is less developed, that is bad for China - Japan was a very important export market for China (even at the height of the cold war).
fasquardon