I think the problem you are running into is that the SELECT * INTO #Table statement is doing double duty as both a table creation and initial population statement.

I am working on a DB project for school and am almost ready to create my tables. I am unsure as to when I turn on referential integrity. Do I create the tables, do my initial data import, and then ...

A developer shouldn't spend time on database table creation when unit tests run. Instead, have Hibernate create tables in the database for JPA and other data-driven applications.