If that comment is in response to my comment immediately above, then NO, I am not talking about the cross-hatch or lines fill (not available on Eagle) options. If you think of the fill as a vector rather than bit map, the fill is with lines that touch. The thicker the line, the more jagged will the edges be. The thinner the line, the more processing it takes. Eagle used to have a warning to that effect. Line width does not affect the gross appearance of the filled areas in Eagle, unless you pick the cross-hatch option.
Just to clarify, there are multiple ways to do what you asked in your first post. Your later post on page 2 illustrates one of the problems of using isolate as the variable. Of course, you can avoid that by using multiple polygons. The restrict method avoids that too, and I find it easier to do in a controlled and precise manner. In Eagle, isolate and line width can affect other things too, like the the way thermals are made.
Finally, as to the patch of copper that is not connected to anything, that is called an "orphan" in Eagle. You can choose to have them left in place or removed.
BTW, Are you actually a PCB manufacturer or is that just an avatar you like?
John