No. Judges (and prosecutors) have a code of ethics they must abide by. While their prior job might color their thinking, knowingly or unknowingly, they must follow prior case law and the Ohio Revised Code. If a judge doesn't, you can appeal a trial court decision.
If you are facing criminal charges, retain a competent criminal defense attorney. Don't go it alone.
Disclaimer: This does not constitute legal advice. No attorney-client relationship has been formed through this answer.
No, not all judges are former prosecutors. The fact that a judge was a prosecutor does not mean that he will be automatically biased against you. Many court systems have judicial profiles online. I agree with my colleague that you should consider talking to a lawyer about your case. Good luck.
I have been licensed to practice in the State of Oregon since 1990. I am not offering legal advice regarding your question, only general information regarding the law. You are not my client nor am I your attorney unless we sign a retainer agreement.
You can't get a judge removed simply because he or she was once a prosecutor. Judges must follow the law as well as judicial ethics. Many judges are former prosecutors because they are in a position to campaign, usually, in platforms that their career has been dedicated to protecting the community.