I did find that there were not enough children processes running - from php-fpm.log
However the real problem I think is this one:
It is a long line so I copied it to Pastebin:
http://pastebin.com/U3bFW0xf
2014/08/04 16:14:01 [crit] 34287#0: *10 connect() to unix:/var/run/php-fpm.sock failed (2: No such file or directory) while connecting to upstream
Odd - as everything else works?
I am not sure how to debug this further.
I have used the notes extensively, in fact I created a word document as I typed in the commands as Joshuas good instructions have become a bit hard to follow.