MDX Questions

I will take a MDX training in mid November. Here is the list of questions I'd like to bring up during the training. I will be posting answers along the way.

1. The Report Designer auto generated MDX queries have additional 'DIMENSION PROPERTIES' and 'CELL PROPERTIES'. Why are they in the MDX query and how are they used in the report? i.e. (See text in blue)
SELECT NON EMPTY { [Measures].[Build Details Count] } ON COLUMNS, NON EMPTY { ([Date].[Date].[Date].ALLMEMBERS ) } DIMENSION PROPERTIES MEMBER_CAPTION, MEMBER_UNIQUE_NAME ON ROWS FROM [Build] CELL PROPERTIES VALUE, BACK_COLOR, FORE_COLOR, FORMATTED_VALUE, FORMAT_STRING, FONT_NAME, FONT_SIZE, FONT_FLAGS

2. I got an error message saying "The Team Project hierarchy already appears in the Axis2 axis." Does it mean that the Where clause only takes demensions that are not in the Select clause?

SELECT {[Measures].[Work], [Measures].[BizStoryValue]} ON COLUMNS,
{[Work Item].[System_Id].[System_Id]} ON ROWS,
{[Team Project].[Team Project].[Team Project]} ON 2
FROM [Current Work Item]
WHERE ([Team Project].[Team Project].&[11])

3. In our TFS process template, there are two fields in Sprint Details work item that has reportable property set to "detail". How to get their value in MDX?
-I found the answer for this question before the training. "Use reportable="detail" to add a column to the fact table without adding anything to the cube."

4. Which is better, select from (Select ....) automated MDX or filter?