Converting to MP3 causes iTunes to Not Respond while using 50% CPU usage and makes my computer stutter

Question

Anytime I attempt to "Createa an MP3 Version" of a track, it will take a REALLY long time to work.
Right now I am attempting to convert an audio book I have which has 88 tracks.  Once I start to convert anything more than 1 track at a time, iTunes immediatly becomes "Not Responding" and takes up about 50% of my CPU the entire time.  It seems like it's doing something in the background but it won't even update the screen anymore, creating weird effects on my screen (Ghost menu bars show up at the top of my screen, etc.).  In addition, once iTunes becomes non-responsive, my entire computer starts to "stutter" meaning that every other second everything momentarily hiccips and stop for a split-second.  This means that while iTunes is converting any multiple MP3 files, if I drag the mouse across the screen, it stops every other second.  Any videos that I try to play pause every other second briefly.  Basically, my computer becomes almost unusable.  Plus, while iTunes is working in the background, different programs randomly jump to the front of the screen.  I will try to be using my web browser while iTunes is working in the background.  Then, suddenly, iTunes pops back up to the foreground in front of my browser (put still won't be responsive to clicks).  My notes program will also flash windows in front of my web browser while surfing, again, only when iTunes is running in the background. 
I really don't understand:
1.  Why it takes so much time to convert any file to an MP3 file.  Even converting a single track takes a few minutes.  I'll let my Macbook Pro (with Windows) sit for HOURS upon hours trying to convert the 88 track audio book and it always freezes up and never comes back.
2.  Why iTunes becomes non-responsive so quickly and won't allow the screen to update once it starts "thinking."  It caps out around 50% of my CPU power so it's not like it doesn't have the headroom to refresh the screen while it works.
3.  Why does iTunes' working in the background affect every other program I am running?  I don't mind if it uses up CPU cycles in the background, but if it makes my computer unusable while doing so, it's really not worth it.
I should state that I love Apple products (even though I use Windows on my MBP for school purposes).  However, I absolutely DREAD having to do anything with iTunes anymore because it has become such a hog on my computer.  Someone please tell me that there is something wrong with my iTunes and/or a setting I should change.  I have already re-installed iTunes from scratch before and that didn't help.

Answer 1

Not a solution, but if the Podcast feed is dormant, why not unsubscribe?
As to the file structure for media on the device it is deliberately obscured as a countermeasure to casual piracy. See Recover your iTunes library from your iPod or iOS device. Content put on the iPod by a non-iPod aware product is going to treat it like any external drive. The iPod firmware won't read that media.
tt2