There are 6 Issurim (by my count) that involve not eating/drinking certain foods. Most are to avoid marrying Goyim; some are for Kashrus.
Stam Yeinam is the most strict. We treat it as mostly Assur B’Hanah because there is an added worry that maybe the Goy was Menasech it for Avodah Zarah.
Pas and Bishul Akkum are to avoid intermarriage. There are several Kulos for each of these in cases where their is not an increased level of familiarity (e.g. the food is not fancy or the bread was made by a baker to sell).
For Chalav and Gevinas Akkum, we are worried about the non-Jew mixing something Treif in. By milk it is that there is actual Treif milk mixed in; by cheese it is the enzymes to cause the cheese to form.
There is a sixth Issur of using oil produced by a non-Jew which the late Tannaim were Mattir because they saw that the majority of the population could not handle it.
Chodosh is an entirely separate Issur. Pashut P’shat is that it is an Issur D’Oraisa, even in Chutz L’Aretz. There are many complicated (and some not-so-complicated) reasons given for the Heter. Even though Pashut P’shat would be that it is Assur Mi’d’oraisa anywhere, Chalilah on anyone to say that the vast majority of Ashkenazi Jews have been violating an Issur D’Oraisa for the past 1000 years.