It is uncertain which tornado was the strongest, as most tornadoes do not have their winds measured. The highest recorded wind speed was in the Moore, Oklahoma tornado of May 3, 1999. Another possible candidate was the Xenia, Ohio tornado of April 3, 1974. See the links for pictures and video of those tornadoes.
The Greensburg tornado was an EF5, the strongest category of tornado.
The strongest winds in a tornado are typically on the right side of the tornado's path, known as the "right-front quadrant." This area can experience wind speeds exceeding 200 mph, making it the most dangerous part of the tornado.
It depends on the tornado. If it is a single vortex tornado the winds near at the edge of the core will be the fastest. However, many of the strongest tornadoes are multivortex, meaning that they have smaller vorticies (almost like mini tornadoes) inside the main vortex. In a multivortex tornado the fastest winds are within these subvortices.
A tornado
tornado
around a tornado
earthquake
Suction vorticies as smaller columns of rotating air within a tornado. They have more intense winds than the rest of the tornado. The suction vortices sometimes look like "mini tornadoes" moving around inside the main circulation.
It depends on the tornado. In most tornadoes the strongest winds are near the center. In multivortex tornadoes, however, the strongest winds are in the subvorticies, which are almost like smaller tornadoes within a larger one.
Both are, but it is probably more likely with a tornado.
The main part of the circulation of a tornado when the strongest winds occur is called the core.
tornado alley