I agree that they are people who are too uninformed to be allowed to vote. Watch Leno's on the street interviews sometime (et.al.). It's horrifying to think that these people vote. However, I do not agree with any of your choices for determining qualification.
Speaking and reading English should be required. However, that's difficult for some native born citizens! Doesn't mean they don't understand what's going on. Being able to read and write isn't even prerequisite for high government office. Look at AG Holder. He voted against the AZ law without even reading it.
One thing I do agree with is that all should be required to perform extensive public service (years) to qualify to vote and for naturalized citiazenship. Now let's figure out what "public service" should be required and get the amendment process underway.