Hi, i am really new to this forum so i apologize if this question has been asked already. We had a very rainy summer so far and yesterday i noticed that there is mold developing between the inner cover and the feeding box. Is this dangerous and what is the best way to remove it, clean it out completely?
Yes -- a hive needs to be warm and dry. Mold/moisture will eventually lead to disease and sick bees. I would immediately work on improving air-flow in your hive. It can be as easy as adding a stick to a corner between cover and inner cover or as complicated as adding a nice ventilation box which I use in the Northwest where we have lots of similar issues.
I wouldn't worry too much about existing mold and first get airflow right.