Hi, Rex,

The answers to your two questions are:

1) I guess your files are either Java or C/C++ files, right? The preference setting "General -> Editors -> Text Editors 
-> Displayed tab width" sets the tab spacing for general file types like .txt and .html; The tab spacing for the Java or
 C/C++ files are controlled by their "Code Style" settings. In the other words, the Java and C/C++ settings override the
 general settings. For example to set the tab spacing for C/C++ files, go to the preference "C/C++ -> Code Style", 
select a profile (K&R [built-in] by default), edit the profile, change the "Tab size" setting. You have to rename the profile because you can not save a built-in profile. For Java files, the same setting is at "Java -> Code Style -> Formatter".

2) For Java or C++ class files, the method decoration "red square" signals a private member. This is the built-in 
annotation and you can't change it. The problem you see that you can't go to it seems to be because of the delay 
processing of the outline view. If you open a big class file which has many class members, the outline view needs 
sometime to fully process the file structure. I saw it once today while trying to open a big header file. I had to close
 the file and re-open it and everything worked fine. Maybe it's a bug in the Eclipse platform or CDT. 

Hope my answers help. Please let us know if you have further question.

Thanks,
Andy