Another steep learning Curve.
A quick comment, following some discussion with other Drupal developers and interested parties last week at the last Bristol & The West, UK Drupal group meetup. It quickly became clear that my search for simplicity in themeing Drupal is ultimately doomed. I know too many ways to do things, there are too many valid approaches.
The consensus appears to be that the skill-set and availability of members in the team will make a huge difference. Having a front-end developer that does not know Drupal inevitably moves a lot of the load back to the back-end developer (or at least introduces a heavy training/knowledge sharing penalty).
Although I can imagine a happier world where the developer is mostly concerned with making sure that the data is there and managing the display tab and view modes in content types, there are lots of times where this is simply not practical.
I shouldn't need a helper module to give me clues about where various bits of the page are being themed. I may have to trace theme functions in the code or trawl through a disparate set of template files that individually give no clue to their heirachy or conceptual inheritance.
Quite a few people seem to be looking forward to Twig in Drupal 8 another post on that soon I think.