Rem,
You asked: When you say "we believe" and "those who believe", what other person are you referring to?
I see you are not well read on this subject matter. A belief that the flood of Noah's day was a flood confined to the land of Noah is a widely held, and widely taught, belief by many Christians. Maybe the "person" you are referring to is Carl Olof Jonsson, the exJW turned Christian author of "The Gentile Times Reconsidered" and "Sign of the Last Days - When?", since I mentioned in an earlier post that he is an advocate of the local flood. But there are many Christians who believe basically the same thing.
Dr. Hugh Ross, a highly respected, widely published and often quoted Christian astronomer teaches that the flood was confined to the land of Noah. His web site is http://www.reasons.org/ . Davis A. Young, a Christian professor of geology at Calvin College in Grand Rapids Michigan, believes as I do. He has written several books debunking Young Earth Creationism and the ridiculous "flood geology" popularized by Morris Whitcomb's "The Genesis Flood." Among Young's books are "Creation and the Flood," "Christianity and the Age of the Earth," "Science Held Hostage" and "The Biblical Flood." His books can be purchased at Amazon.com, as Ross's can be. This understanding of Noah's flood is also being promoted today by the Christian author
Richard Fischer. Fischer graduated from the University of Missouri with a Bachelor of Science degree. His first article on religion was published in The Washington Post in 1986. He received his master's degree in theology in 1992. He has published articles in Perspectives on Science and Christian Faith, and has reviewed articles for publication in Christian Scholar's Review. He is a member of American Scientific Affiliation, Interdisciplinary Biblical Research Institute, Evangelical Theological Society, and he is listed in Who's Who in Theology and Science. Fisher's book on the subject is entitled The Origins Solution. It too can be purchased at Amazon.com. Or you may want to just crack open a couple non-fundy, non-JW, Bible encyclopedias. I have the five volume "Zondervan Pictorial Encyclopedia of the Bible" on my shelves. It has a very good article on why the flood had to have been confined to the land of Noah. I could go on, but that should be enough to get you started.
You asked: So god was so concerned about this little plot of land on the earth that he flooded it, but made arangements for Noah and his family and the animals in the area to survive. God didn't seem to care about the wickedness in other parts of the earth.
Some Christians who believe that the flood of Noah's day was local believe that at the time of the flood the entire human population of the earth was confined to the land of Noah. Those with a background in earth sciences, such as the authors Young and Fischer mentioned above know better. Since they do, they understand as I do, that God intended for the judgment He brought upon Noah's land to serve "as an example of what is going to happen to the ungodly." (2 Peter 2:5,6)
You asked: When he said regretted making man on the earth, he really only meant this little area that Noah could preach to in the Middle East?
Substitute the words "in the land" for "in the earth" or "on the earth," as the Hebrew language allows us to do, and you should have less trouble understanding the verses you cited.