For me, as an atheist, prayer would be a waste of time since I would know that there is no one listening. However, I believe that it is not necessarily a waste of time for believer to pray, since prayer, by itself, may be a source of comfort in times of trouble. This applies equally to the prayers of Christians, Muslims, Hindus and all others.
You are talking to God.
No, you cannot pray before prayer time because prayer time is specifically designated for prayer.
This is a very broad question. It depends on your personal beliefs. Some Christians, for example, believe that all prayer is valuable, however, some believe that prayer for material things is a waste of time, or prayer for anything outside of God's will is a waste of time: IE: "Please let me win the lottery" or "Please help me buy a new TV." Generally speaking, Christians don't believe that God is a wish granter sitting in Heaven waiting to grant your every request. However, I would say that if a person believes in the power of prayer, and that if the act of praying helps a person cope with day to day stress, or if it just simply makes a person feel better, in a general sense, it is not a waste of time. But again, it's a matter of personal belief. An atheist would probably say that it is a waste of time, and that since there is no God, you might as well be talking to the wall.
Tahajjud prayer can be performed any time after the Isha prayer and before the Fajr prayer.
The Dhuhr prayer can be performed until the time of Asr prayer begins.
The Fajr prayer time ends at sunrise.
The Isha prayer time ends at midnight.
The shuruq prayer time begins shortly after sunrise.
IT IS A WASTE of time because it is not necessary to do it is a waste of time
An arrow prayer is a very short prayer, suitable for uttering at any time.
Yes, you can pray at any time, including before the designated prayer time.
history is a waste of time.