1. Its actually a very broad number of countries if you base it on how they vote at the UN. If instead you look at whether these countries trade with Israel, the number shrinks significantly. For many countries, it is normal to condem Israel and then to buy Israeli goods. Indeed, many countries both denounce Israel at the UN, and buy Israeli produced weapons. An example of the “bark” being worse than the “bite”?
2. In many countries, the major products we import are produced by the local Jewish community for the kosher market so it wouldn’t accomplish much to boycott these products. The fact that a product has a kosher certification is probably much more important than the politics of the government of the country of production (and if the product doesn’t have a hecksher, why buy it to begin with).