Baron, any training or checking failure at the 121 level is not good for your career progression to a major airline. That being said it's not impossible to have a clean record: study well, prepare to the best of your abilities, be a professional and knock it out of the park. As you said some regionals have notorious training departments with high washout rates. This is intentional and my belief is that it is for liability reasons. Too easy and they leave themselves open to lawsuits in case of an accident. Be knowledgeable about who wants to put you in their new hire class.