Is it possible to save the map ingame? I haven't looked at the API so much but what I have seen it aint build in.

Try

FormatManager.DefaultFormat.Store(map, stream);

where map is your map object and stream is a stream object that you can set to a file stream.

This is just really good so I can make a ingame map editor :)

using (FileStream stream = new FileStream(@"F:\TE\Test\File.xml", FileMode.Create, FileAccess.Write, FileShare.None))
{
      FormatManager.Instance.DefaultFormat.Store(map, stream);
}

using (FileStream stream = new FileStream(@"F:\TE\Test\File.xml", FileMode.Open, FileAccess.Read, FileShare.None))
{
     map = FormatManager.Instance.DefaultFormat.Load(stream);
}

You got the gist of it :)

I noticed that you have that feature. But there was one thing I got a bit confused on and I don't want to mess around with the Source due to it will just make all more frustrating. But how do you load all the tilesheets? From what I know 'Initialize()' is called before 'LoadContent()' Or is it reinitialize it? 

Becosue if I use

map = FormatManager.Instance.DefaultFormat.Load(stream);

Will it reinitialize it? Or yeah... I just want to know how it load all the tilesheets.

You have to call map.LoadTileSheets(displayDevice) after you load your map (or at least before you attempt to render it).

Okey, I did test it out and see what did load first with Debugging and found out that LoadContent is Called before Initialize. So I understand it now.