1) Yes, but apparently they are updating the servers, so be patient.
2) Yes, like al GNU/GPL software.
3) If you don't have a DVD writer, why would you want to d/l a DVD version? You *can* use DVD+R discs as well.
4) Yes.
I suggest reading the README file, the cheatcode-file and use Google to find HOWTO's and user experiences. It's all out there [on the net], it just requires some more effort on your part