Does OO support macro programming?
According to the help file, yes it does.
Which programming language is used for macro's?
See below.
As for the rest of your questions - I've no idea - dont use macros.
However, this is what it says about Office macros :
Microsoft Office and OpenOffice.org cannot run the same macro code. Microsoft Office uses VBA (Visual Basic for Applications) code, and OpenOffice.org uses Basic code based on the OpenOffice.org API (Application Program Interface) environment. Although the programming language is the same, the objects and methods are different.
If you use macros in one of the applications and want to use the same functionality in the other application, you must edit the macros. OpenOffice.org can load the macros that are contained within Microsoft Office files and you can then view and edit the macro code in the OpenOffice.org Basic IDE editor.