I\'m using Visual Studio 2010 with some add-ins and extensions. The problem is now that the context menu of the project items in the solution explorer is getting so large that I
You can always use the keyboard to do the work for you.
The keyboard bindings are set under Tools->Options...->Environment->Keyboard, and the interesting settings in this case are probably View.SolutionExplorer, Project.OpenFolderinWindowsExplorer and View.PropertiesWindow or Project.Properties depending on which propertiy collection you were referring to.
Yes, it can be edited.