1 Yes, you can, but it sounds much more natural without 'do'.
2 I am to blame for this fiasco = I am responsible for it and accept it
I am to be blame for this fiasco
I am to be blamed for this fiasco- people will hold me responsible, but it could either be the case that I am responsible or, in most cases, that I feel I am innocent and being treated unfairly
Student or Learner