The default homescreen in Android can be changed by doing the following:
Open the Android settings
Click on "Applications"
Now press "Manage applications"
Now find the currently selected homescreen. The default Google homescreen will be called "Home" or "Launcher" depending on the version of Android you are using.
If you are unable to find the current homescreen it might be that the list is filtered. If this is the case press the menu button and select "Filter"
Now press "All" to see all the installed applications
Click on the currently set homescreen and you will see all the information about the application. Scroll down to the section "Launch by default". And press the button "Clear defaults" to be able to get the dialog that allows you to choose any homescreen as default.
Now press the home button and you should get a dialog that will allow you to choose what homescreen you want to use and a checkbox to set it as default.
The Application Dock Widget can be dragged / removed by long pressing the far left or the far right corner of the widget.
The desktop transition and menu animation can be changed in the "Animations"-menu which can be accessed from the "Settings"-menu and then "Personalize appearance".
You can also open the "Appearance"-menu by clicking the "Add"-button or long-pressing the desktop.
You can sort items by long pressing and holding the folder ( or an item within ) for 2 seconds. You will now get a dialog which will show an option "Sort items" or "Sort parent items".
You can change the properties of an item by long pressing and holding the item for 2 seconds. You will now get a dialog which will show an option "Edit properties".
The screen selector will show when you are on your default homescreen and you press the "home"-button. The screen preview will also open when you long press the "add"-button on a version-2 theme.
To change the view of a menu that supports switching you can click the top right button in the menu handle ( on the right of the menu title ).
In the menu you can go back by pressing the top left button ( on the left of the menu title ) or your phones "back"-button. If you are already in the main menu pressing the back button will result in closing the menu.