Unfortunately, there is no easy way to take a massive webform form and convert its form fields into a Drupal Entity + Fields. And yes when you want to re-architecture your website and do this for 50+ fields -- it sucks (been there).
Because some things like the Workbench module only work with things that are Nodes. And when you initially choose a webform to represent this data you've coded yourself into a corner.
This is kinda 1 place where Drupal is somewhat lacking -- interopability between similar tools (webform, entityform, entities, ECK, etc).
There are some tools to "move stuff around" such as:
But they only work within 1 kind of architechure (Entities).