If I don't notice that my rosacea gets worse with certain irritants, could I be misdiagnosed?

Not necessarily. rosacea differs in individual reactivity, just like every snowflake is different....diff reactions from other irritants.... that said you can have rosacea and other reactivities as well.....or just be sensitive to some irritants and not have rosacea.
Possible. Rosacea can look like several other diagnoses. Most people with rosacea get worse with the sun and alcohol. Most other triggers vary from person to person.