Honestly, I think they were more interested in your system specs to focus on things they need to test like lower end systems, or a certain generation of nvidia/ati cards on windows xp or vista.

The questions like why you want to join alpha or how long can you play seem like fluff questions to me.

For the most part, you are largely just a warm body in an alpha as they work on server stability.

But specualation on what the "correct" answers were is pointless because only SE knows for sure what their standard is or what reason they choose people. The only thing we know for sure is that if we weren't chosen at this point it is because we can't help them. When we can, they will happily let us know.