As long as your country is offering something that 90% of Earth’s population lacks (access to high-quality free healthcare which is what people usually mean as “universal”) then, yes, you’re going to attract a lot of freeloaders.
I wish I could believe this. Seems more like wishful thinking along the lines of America’s hubris that it could “bring democracy” to the Middle East.
There’s nothing magic about soil. You need to give time for waves of immigrants to integrate, or it leads to backlash and horrible people like Trump getting elected.
I wouldn’t call it extreme, as it has been done before. In the US, for example, borders were completely open for the first hundred years until anti-Chinese racism led to the passage of the Page Act in 1875.