As an outdoor grower who has experienced bud rot (what I see in your pics) I can answer some of your questions.
—Don’t put fans all around because they will spread spores
—Cut below molded part of stem and discard upper molded section.
—Before cutting moldy stems
or buds minimize spore spread by misting then cover with plastic bag and cut moldy parts.
—Don’t put chemicals on buds that are ready to harvest as it makes no sense.
—Don’t stop watering plants still maturing…just reduce watering by half.
—Buds that are ready for harvest but have been exposed to mold spores should be harvested, wet trimmed, and dried normally in a room with a dehumidifier and AC if needed. Lowering the humidity should prevent mold growth and allow for proper drying.
Hope this helps.