Well yeah, but the Christian belief is generally that the Bible is right, if you study it, you'll realise that, and "magic" will be proved when we reach the time of Revelations. If a god wanted to keep proving they were divine constantly without anyone having to think about it or "accept God into their heart", they'd have to keep appearing and doing random "magic" for no reason except to prove they were divine. That would be a very chaotic world and might not be God's real goal.

We might not have seen anything like that in our lifetimes, but most of the religions believe that there were miracles in the times of their prophets, so that was sort of happening in the old testament.

You could say that these prophets and divine figures were magicians, but they then likely would need technology far in advance of their time. Do you think Jesus had elaborate stage tricks? It would probably be more sensible to say at least some of them were lied about or supposed to be metaphorical.

Just because you've never seen something you don't think is understood by physics or other explainable things, doesn't mean there isn't any kind of god(s) that have divine powers.

If God is the ultimate ruler and creator of the universe, God can do whatever He wants. Any belief system will tell you this basically.

You seem to be an atheist, but if you did believe in God then it would be quite silly of you to deny that such a God could perform miracles. If this is all someone's dream, they could imagine whatever they wanted. If I wrote a computer program and was the "god" of that universe, I could make whatever I wanted happen in the program, at least if I was skilled enough in programming, but God would have to be anyway in that scenario.