Thanks Andru for your help! I think the problem was finally solved!
I was loading the file directly using the function TWideStrings.LoadFromFile(String);

Instead of that, I'm using now the class TStreamReader:
- First I load the file using TStreamReader.Create(FileName, TEncoding.UTF;
- This way, the IDE will always assume that the file is a UTF8.
- As far I tested, even if the file is not UTF8, the file is loaded correctly;
- After load in the TStreamReader, I call the function TWideString.Text := TStreamReader.ReadToEnd;

I have a new idea for Layout managment. Since I'm not working with the docking system provided by Delphi, I will create a new form(borderless) which will show the possible layouts combination:
Layout.jpg
Then, you will just select the layout, or make any of the frames visible/invisible.