Can a small airway passage be causing frequent sinus infections?

Theoretically: A "small" nasal passage can lead to frequent sinus infections especially if you have nasal inflammation from a cold, nasal allergies or a deviated nasal septum that is interfering with sinus and nasal mucus flow. Chech with an ENT to assess nasal airway size and sinus anatomy. Nasal endoscopy and sinus ct may be needed.

Maybe: This could make you more prone to them. Recurring sinus infections are more often due to virus(and not bacteria)..They can be caused by frequent exposure to others who have respiratory infections(ie, teachers, students) ;or having underlying allergies; or rarely a "minor" immune problem. See an allergist and ENT for a careful evaluation.