So hard to explain...yes, the meanings are slightly different, but so close that you will probably never need to worry about it. I can only think of one situation where I would prefer one over the other: If I am applying to a job for an international company, I might ask, "Do you ever go abroad?" to question whether or not I will be traveling if I take the job. In that situation, "Have you ever been abroad?" sounds like I'm asking a personal question. In the first question, "Do you...", the "you" is referring to people who work for the company rather than the specific person I'm asking. When speaking to an individual on a personal level, though, I can't see any difference between the two questions.

Yes. The first is wrong. Th second is fine.

"Do you ever go abroad?" (don't put "have" in the sentence) is asking about a person's lifestyle, habits or work situation. It's a general question. This is why we use present simple. "Have you ever been abroad?" asks about a person's experience, ie. from the past up to now. This is why we use present perfect. These are quite different questions. If you're getting to know someone and want to know about that person's experience, then "have you ever (pp verb)...?" is how we ask such a question.

Never,but I have some forign friedns in China,they are very interesting and kind.