There are two major functions of customs. First is to provide a first line of defense against dangerous materials entering the country. If your parcel emits any sort of radiation, you can expect it to be delayed for months in customs as they seek to ensure that no weapons of mass destruction enter the country. The second function is similar, but focuses more on illicit drugs, smuggled goods, or attempts to avoid duty taxes.
The current customs policies were not set up to be an arbitrary nuisance for travelers. Sure, it might seem stupid that you can't take fruit from one country to another, but there are solid reasons for these restrictions. These restrictions prevent diseases from traveling from one country to another and they prevent damage to ecosystems from introducing new animals and plants.
No, customs policies should not be eased worldwide, because enough slips through the cracks as it is. Anymore, thousands of pounds of drugs are smuggled into the U.S. each year. Borders officials are in on it or they just look the other way. They need to crack down on it, no ease up.
Customs policies should not be eased worldwide. This is because more counterfeit merchandise is making it to import and export. If we don't make the rules more strict, then a major part of the retail market will be filled with nothing but counterfeit merchandise. Making the rules tigher will help this and perhaps bring fines to companies that violate trademarks.