that pack includes media player classic, witch as i know playes everything. just install the codec pack with "Lots of stuff" option. u wont get any problems. I used 5.2.0 before i switched to linux testing
klite (lots of stuff option) + klite 64 (so i can have thumbnails in explorer in win x64 bit for mkv and some other).
depends, klite 32bit is if you have wmp12 32bit (aka 32bit win7), klite64 is for wmp12 64bit (64bit win).
Another vote for Sharks Codecs. I use both the 32 bit package, and the 64bit addon. I have 3 Windows 7 64bit systems and Sharks are the only ones that work in WMP and Media Center without problems