Here's a couple suggestions for the codecs:

-replace Matroska Pack with just Matroska Splitter since it can also handle OGM
-take off OggDs because you have Matroska Splitter, and FFDShow can decode Vorbis
-here's a better link for FFDShow: link

The only things I have installed are FFDShow, VSFilter, Matroska Splitter and AC3 Filter. I let FFDShow decode pretty much everything, including MP3. But of course, if I need to encode stuff, the actual codecs are required.

But for newbs, FFDShow might be hard to configure since it has so many options. I personally can't live without the sharpening filter.