Criminal Law Questions? Ask a Criminal Lawyer.
The police must advise suspects of their "Miranda Rights" - their right to remain silent, their right to an attorney, and the right to an appointed attorney if they are unable to afford counsel - prior to conducting a custodial interrogation.
You don't necessarily have to be read your Miranda Rights if the police don't interrogate you after being arrested. Here's a good article about this and other Miranda issues:
It's probably too late to allege a conflict of interest - and if the judge and your lawyer were related, it probably worked in your favor, not against you. If this matter will be dismissed after you complete your probation, it's probably better to let it go than to challenge the deal you got, which could backfire against you.