Air flow through a hive is extremely important. It helps keep the hive cool, dries out the honey, and even assists with temperature regulation in the winter. Prioritizing ventilation in your hive is always a good idea.
Unless you are transporting the bees or deliberately trying to keep them in your hives, always make sure the venthole on the inner cover is exposed. I prefer to have the vent hole on the inner cover on the back of the hive. This seems to allow for better airflow through the entire space.
I prefer to use the screened bottom boards on my beehives. This allows for better airflow and it is more difficult for mites and hive beetles to stay in the hive. Our winters in Oklahoma may not be terribly cold, but we still get plenty of days and nights below freezing. I still don’t block the screens in winter and my bees do just fine. This is because good ventilation keeps the moisture down and cold moisture is much worse for the bees than cold alone.
I have experimented with drilled holes on the front of my honey supers with great success. I drill a ½ hole on the front of the medium super above the handhold. This improves ventilation and helps the bees with access. The bees wax the super and fill it with honey much faster.
Always prioritize ventilation for your hives. There are a lot of bees in one hive and making sure it can “breathe” is important for their health.