Londo, your myths are spot on.
For a long time I didn't know why I felt so disoriented after being reinstated. Then I realized it was because while I was DFd, I had been told repeatedly that I was a nonrepentant practicer of sin who had to be removed to protect the rest of the congregation from being contaminated. They told my children I was not allowed to have a Bible study with them or talk to them about anything related to the religion, even though I had been faithfully teaching them "the truth" from the time they were born.
AFter I was reinstated, I realized that they had lied. I had been put through hell by three men who did not know who I was inside. I was the same person I had always been. I was not an unrepentent sinner, nor was I a danger to the congregation. Never had been. I had been the most faithful of the faithful, following all the rules. But I was lonely and discouraged. Many times I tried to get help and encouragement from the elders, but they never had time for me. In fact, when they called me to set up a meeting to DF me, they didn't even tell me it was a judicial meeting. I went in there thinking I was finally going to get some shepherding help. What a surprise.
I attended the meeting the night they announced it because I wanted to show my humility and desire to remain in the congregation. They were angry and told me to leave, that I was being disrespectful. I requested reinstatement two months later for the same reason. They were angry and told me I was being disrespectful because I had to wait at least a year. It didn't matter what I did, they interpreted it the way they wanted to.
I know many who had the same experience. I was the same person before and after being DF and reinstated. I was a faithful believer of the religion. Nothing had changed. But three men had the power to destroy my life by telling everyone something different about me. It was like Monday I was a faithful witness in good standing. Tuesday I was an unrepentent evildoer. By the time the weekend came around, they had decided I was a faithful witness again. When I realized that, I knew I wanted no part of being a JW anymore.
I just want to reiterate your two key myths about disfellowshipping:
1. The elders make subjective decisions on repentance and they are mainly guided by personal opinion.
2. Most who are DF'd are good, faithful witnesses in everything else except the offence related to being DFd. They are not actively trying to turn the rest of the congregation to wrongdoing.