I am unable to access the iTunes Store, but all other features of iTunes are normal.

Question

I always get a message "We could not complete your iTunes Store request.  The host is down.  There was an error in the iTunes Store. Please try again later."  I have downloaded and reinstalled the current version of iTunes (11.0.2 (26) 64 bit) with no effect.  I have not had any other problems with iTunes.  I have not had any problems with Internet access.

Answer 1

Very unusual to have 69 itunes plist files in ~/Library/Preferences.  Also unusual to not have one in ~/Library/Caches.
If it were my computer, I would trash all the ones in the Preferences folder, and double check for one in the Caches folder, and trash it if you find it.  I'd also consider trashing the iTunes folder in ~/Preferences.  Do this with iTunes quit, first.  None of this touches your library, but you should have a backup before doing things like this.  Or instead of trashing, back them up on your desktop like before, just in case.
Don't open itunes yet.  Then, maybe a permissions repair on your home folder is in order.  You may try this first, if you like, and possible should, since your app store isn't quite right either:
Shutdown, boot to recovery (hold CMD + R).  You may be asked to select your language and you'll end up at OS X Utilities.  When there, ignore that window, select Utilities at the top of your screen, then Terminal.  Type in "resetpassword" (no quotes) and press enter.  On the window that pops up, select your boot drive at the top (likely Machintosh HD), your user account (likely selected already).  Then, select Reset near the bottom to reset your ACLs.  This may take a few minutes depending on how many files you have for the reset to go through.  When it's done, close the window and the terminal window.  Then click the Apple in the upper left, restart, test.