1. read about
mpegplayer - video playback on the iPod is terrible, this is due to the fact that rockbox does not currently use the Broadcom video chip, there is no public documentation to help the devs so I wouldn't expect video playback to improve dramatically soon. solution: use the apple fw for video
2.no, definitely not.
3. see the extras link on the sidebar
4.Ifranview is good
5.patches need to be applied to source code, and then the source needs to be compiled into a build. For an intro to patching/compiling read :
http://www.rockbox.org/twiki/bin/view/Main/SimpleGuideToCompilingsince it looks like you are new to this, I'd recommend looking in the unsupported builds forum for one that includes the patch you have, much easier than compiling.