Using char tokens can definitely be helpful, as can sub-words. It's something we've been working on too, and hope to show results of this in the future.
I mainly disagree with your view of end-to-end training. In computer vision we pretty much gave up on trying to re-use hyper-columns without fine-tuning, because the fine-tuning just helps so much. It's really no trouble doing the fine-tuning - in fact the consistency of using a single model form across so many different datasets is really convenient and helpful for doing additional levels of transfer learning.
Thanks for the note about table 7 - it's actually an error (it should be 5.57, not 4.57; Sebastian is in the process of uploading a corrected version).