Noob Map editing question

[Xietor]

I made a random map, and I am trying to edit out all of the waste squares. I go to edit map, add the name, Big map" and proceed to uncheck all of the squares where it has waste marked. Then I hit save map and give the map a new name. The map appears in my map files, but when i go to create a new game, the edited map is not given as an option.

So I have 4 questions:

1. What is the step by step procedure to get rid of waste squares on a randomly generated map.

2. Can I change a land square to water on a randomly created map? If so will the terrain feature change on the edited map so that it looks like water?

3. When creating a random map, is there any way to minimize waste squares?

4. Starting capital: is there any way to designate the starting human player capital on the map?

Thanks in advance for any assistance!