I don't know about 4.) but for the others it sounds like you're looking for lucid dreaming. It's not a spell, it's a technique. Keep a notebook to write your dreams in, ask yourself during the day, "Am I dreaming right now?" And test the reality. Later, when you dream, you can do the same test, but the test will make it clear that you are in a dream and not awake. Then you'll be vigilant and wise.
Or you can simply pay attention as you fall asleep, make your own dream, use your imagination while you're sleepy and you will have a Lucid Dream.
For dream-sharing, I've only heard of it happening by accident.
1. When we are asleep, we're half-vigilant.Is there any way so we can be completely vigilant in our dreams and do acts wisely?
Yes, there is. We have a way of controlling our dreams (called lucid dreams) and making our own descisions then.
2.Is there any way so we can break into someone's dream?
"Breaking into someone's dream", I don't think so. You can enter someone dream, but I don't think you can break into a current one.
3.Is there any way to share a dream and have common dream?
Yes. There is a method, I think, called dream walking. As I said before, you can enter someone's dream, and invite them to spend that short amount of time with you.
4.Is there any way so we could sleep or make someone sleep very quick (using magic) ?
No, there isn't.
5.Is there any way to have a real imagination (like dreams), I mean make our own dreams and chose what we'd like to happen ?
Yes, this process is called Lucid dreaming. This is where you are able to control you dreams, and do what you would like to do.
6.Is there any way so we can see a real dream ??? I mean be in a place we have never gone (like what's happening right now in another place) or be in a time we never was (like 1000 years ago) ???
I don't fully understand this question. You can't be in another physical place while you are sleeping, and nor can you go to another place "life 1000 years ago". There are other methods to what you would think 1000 years ago looked like. Astral projection, which isn't directly related to lucid dreaming, is where you are able to do anything on the Astral realm that you can't on the Physical.
Some sedatives or tranquilizers can do 4.) for you, but the ones that are effective are too strong to be safe.
Sharing dreams just happens. The theory is that there's another world that's also real, that people can more easily go to when they're asleep, so they share the experience of that world. You can become lucid in a dream by keeping a dream journal in waking life, making reality checks, or meditating before you sleep.
To break into someone's dream, can sometimes be done with a vision quest. Some healers connect with the person that they're trying to heal, and they experience this person's soul as a world that they can travel to. If something is missing in the world, then that means something is missing in their soul, so they must travel to find that symbol, and the healing happens when this symbol is restored to the soul. It's all meditation. It seems like a dream, but the one who needs healing can be awake during the process.
6.) You might be looking for out-of-body experiences. I've had those before. They're difficult to control. This one person tried to test it by leaving a playing card somewhere in the same room that they could only see out-of-body. They drew the result: