1) Yes i would, SD is very reliable when it comes to their services, so i can safely recommend downloading the game through them rather than trying to find a physical copy of the game somewhere.
2) Download speeds while downloading for me were usually around the 520 KB/s mark, which is infact the maximum for my connection. So you should be seeing a pretty decent speed.
Total download is just over 1GB, so at that speed downloading it only takes 40 minutes or so. Infact, most Demo's of current games are larger than this.
3) The manual is included in the download, you can find it in the game directory after installing.
