I believe in honesty, and sometimes the truth can hurt people’s feelings but that is their problem. I find that holding back the truth or lying to placate others does a disservice to everyone involved and perpetuates the head-games that created a lot of our messes in the first place. Some matters are trivial and not worth mentioning, though.
With that being said, if you no longer live at home, what is there to fight about with your parents? Once you are an independent adult, they no longer have any control over you except the control you give them.
From personal experience, I learned that placing blame and pointing fingers means that your choices are still being manipulated by them in some way or another. They made mistakes or poor decisions. The extent to which they have fucked up will vary, but all humans do make mistakes. In my case, I was emotionally neglected by my parents, which made me more susceptible to psychological and sexual abuse from another family member. I had a lot of anger that kept me trapped for decades.
The past can not be changed, and your parents can not be controlled. The only thing that you can control is what you do with the current moment in time. If your actions and choices are determined based on should-haves and what-ifs, you are not acting independently, rather you are reacting based on your past. Let it go. Take accountability for what you do with the here and now, and consider your actions based on the future you want for yourself.
Some of us have to walk away from family members, old friends and even lovers because those relationships are unhealthy for us. If your parents are still trying to manipulate you after you’ve left the nest, then it may be necessary to pull away to some extent – if not completely. Consider writing a letter to each of them. On the first draft, let it all pour out and fully vent your emotions. On revision, try to find more mature wording to express your feelings with evidence to back up the points you are making. If at this point, you are still considering sending the letters, revise again to streamline your points down to the core issues.
There are many posts here on Fluther about dysfunctional family relationships, search through the archives for more insight to how many of us have coped with our own situations. Good luck!