I like this configuration. However, (and this is just a personal opinion) I think there should be some way of telling Emacs which org file to tangle automagically without it having to have to be inside the ~/.emacs.d directory.

My reasoning behind this is that I sometimes write literate programs and need this feature and think it's nifty to have when needed. Maybe having a keyword like a file category that tells emacs to tangle the file automagically. For example:

#+TITLE: Some title
#+Category: tangle