The district court considered the case on the suit

The district court considered the case on the suit of Ulyanova to Polyclinic No. 2 for compensation for harm caused to the health of the plaintiff as a result of a medical error. At the hearing, the plaintiff challenged the judge considering the case, on the grounds that he was being treated in this clinic, and therefore was in a certain dependence on the defendant.
Questions:
1. Are there grounds for satisfying the stated challenge?
2. What is the principle of the independence of judges and their subordination only to the law?
3. Expand the content and meaning of this principle.
Additional questions:
1. What are the principles of civil procedural law that are constitutional in nature and what are the consequences of a court violating such principles?
2. Describe the composition of the courts hearing cases in the first and second instances.