They are legally obliged to for any sales to the US territories. So if you are in the US and buy Minecraft, then they are exporting software to the US and have to comply with relevant law and any trade agreements between Sweden and the US.
Second. There cannot be and there is none agreements between Sweden and US which would prevent swedish companies producing something that infringes US-only patents. Also any swedish company can produce anything that is banned in US. I guess absynthe is.
Third. Pay attention to the HTC & Apple cases. Apple is trying to prevent import of HTC phones. That is the key! Apple can not sue taiwanese company of US patent infringement, not in US, not in Taiwan. What they can do is complain to ITC and ban import and that is exactly what they ar doing: http://www.fosspatents.com/2011/12/apple-wins-itc-ruling-of-...
Second. That is not how import/export law works. I do not have time to explain how it applies, so Google it.
Third. Your second statement is correct.
Fourth. Your third statement is not correct. Apple can sue HTC in the U.S. b/c HTC does business in the U.S. Apple chose to pursue this case in the ITC b/c it is asignificantly faster way to achieve its business goals (namely, interfering with a competitor's sales of a product). Patent litigation through the court system is a very slow, years-long process, and could take long enough that Apple would be on the down-cycle again.
The liquor analogy would be if you ordered a bottle of liquor to be shipped to the US and the liquor store would be expected to comply with US import rules.
> liquor to be shipped to the US and the liquor store would be expected to comply with US import rules
It may want to comply with the rules, because the parcel will bounce at customs, but if there are no export restrictions, it has no other reason not to send a bottle into the US.
Except to serve it's customer, because if it doesn't meet import requirements then the customer's package will never arrive. I understand it may not be legally obligated so there's no repercussion except the shipment being confiscated, but it's in business to serve customers.
Carrying stuff you bought on an overseas trip through customs is not "importation" for legal purposes.
Also, export restrictions are different from import laws. Export laws are applied by the seller's country. The buyer does not have to comply with export laws. Import laws are applied by the buyer's country. Both the buyer and seller must comply with import laws unless the buyer is an "importer of record" in which case only the buyer must comply with import laws.