Well, its best to install the CCCP and use the Media Player Classic it comes with. Heres a link: http://cccp-project.net/
Once you install this, the files will work on Windows Media Player also, but Media Player Classic is best.

As for the other questions:

1. The Dubs are decent, but the accual anime with the subs is better, and less annoying.

2. The subs are good, don't worry about that.