Is it a problem that I see daylight through my shed's soffit?
My shed has (better-sheltered) gaps.  I believe my shed's gaps are on purpose, to enable air circulation.  This prevents mold and mildew problems in the unheated space.

I am surprised that your shed has fiberglass insulation in the walls, but not in the ceiling.  With no heat, and so many thermal bridges and air gaps, I would be surprised if the insulation noticeably affects the temperature inside the shed.