I'm no expert but this is what I think I know about taxes:
Customs taxes or import taxes is an old way to regulate the market. It is mainly done to protect the companies of the country. It adds taxes on imported goods so that people prefer to shop from local companies rather than send money out of the country.
A lot of countries have had this kind of taxes until they have joined trade agreements with other countries. Like the EU, NAFTA and similar.
Some times special kind of goods get very high import taxes if the goods are in direct competition. For instance I believe both the EU and the US add high taxes to food from Africa or South America.
In additions customs are also used to regulate dangerous or illegal material being imported, like drugs, arms or similar.
As for any countries being more tyrannical than others, I don't think the EU is any worse than the US, and other countries might be even "worse" or more protective.
Value adding tax, or VAT, is generally added within a country to alter the price levels of goods. This both to regulate the usage of goods, to compensate for damages or costs infilicted by them or just as a convinient way to bring more money to the government and spread it on other social benefits.
This levels vary of course from country to country. Some countries have separate taxes in addition for "damaging" goods, like tobacco or liquor.
In Norway we've had very strict laws regarding alcohol, and still have high taxes. They are intended to lower usage and to spend the tax money for hospital bills or other damages caused on society.
I don't think people agree on wether it actually helps to get the usage/abuse down, as people are more likely to try to make their own alcohol or illegally import such things (or buy it from people who do).
We're seeing lowering taxes on import and export throughout the world and markets are getting more and more open as countries adapt to a global economy, but there are still very few countries that don't protect their own markets using this kind of taxation or restrictions.
As for sending a parcel from the US to Norway, you would probably sign a standard form stating its content and its price, and wether it's a gift or not. The recipient would get a notice that he has got a parcel and a request to process it thru customs, he can conviniently let the Postal service do that or choose some own methods. If it's a gift, I believe there will be no taxes added.
If it's a purchase he gets the usual VAT added (added to all goods bought in the country), and depending on the type of goods or price, gets another import tax added.
Currently we can import goods that are worth less than 200 NOK without any taxes added, at least this is true for online shopping. I'm not sure what the level is for travelling into the country with goods, as there are separate tax-free rules and similar.
I hope this answered some of the questions and that I'm not presenting incorrect statements
