There is no "EU" passport, only passports of countries in the EU. I'm pretty sure you have to be 18 to attempt to immigrate (although that doesn't stop many teenagers from going for it by working under the table until they can get a legit job to sponsor them, and pls do not think I'm encouraging that!)
We have two American families in our 'hood whose husbands/wives are well into their 40s (both moved because of the situation in the States, one has a non-binary child). So, looks like it can be done.
There are tons of articles in English about the 30% ruling just search for it. There are two official government sites, again in English, but they are kind of dry.