Did you try Preferences \ Display \ Affected highlighting ? select -hi is not select branch, it is Select Hierarchy, an option that you can access through the Edit Menu, or Right Click and one of the options in the lower menu. It's not that difficult. You can also assign the command "SelectHierarchy" to a key, a custom marking menu or a button in your shelf.
We all know that Maya isn't the most friendly 3d software but don't exaggerate, you don't need to know scripting at all to select a hierarchy. You just need to know how to use Maya interface. Select Hierarchy would be like select branch and then select child nodes in Softimage. There is nothing like Select branch in Maya. Martin
