Hello, Tanya
Welcome to the forums.
All of your sentences are correct.
In the case of "Tokyo", also both options are correct, even if Tokyo still is the capital city of Japan.
Here's a similar case in which most people will use the past tense for a present situation:
Suppose you're at work. It's 5 pm, so everyone is leaving. You're working extra hours and when you leave, at 6 pm, you find that one of your workmates is still at the office too. You look surprised because you thought everyone but you had left already. So, you can say, for example:
"I didn't know you
were still here"
even when the person
is there right now, at the moment you're speaking.
Of course, though, you have to take the context into account. In the following situation, only the past tense makes sense:
You are talking with a friend about education in Bangladesh. Your friend tells you:
"There weren't enough schools in Bangladesh in the 1970s." (I'm making this up, I really don't know anything about schools in Bangladesh)
If you didn't know that, you can't use the simple present to express it. You will probably say something like:
"I didn't know there weren't enough schools in Bangladesh (then)."
I hope it helps.
Miriam