http://telemedicine.org/stamford.htm
On the left-hand index click onto the diabetes in skin disease and read away. You should find parts of your explanations there, tho not all. It all is connected to the 'whole'?
I am like others here.. lots of changes occurred and still occur due to the neuropathy.
As for the tendon shortening...do ask for Therapy! Learn to do stretching exercises that are SAFE for you! If you can't get therapy from your docs either appeal or get a second opinion...it is imperative to keep those muscles and tendons as flexible and fit as possible for the longer term. By doing so, you could avoid other damage and injuries in the future.
I hope this helps! - j