My soffits are covered with insulation. Do I remove all insulation over the soffits or push it back and put sleeves in?
This is really two questions. As far as the insulation, you are right to move the insulation to allow the air to circulate from your soffit vent to your ridge or turtle vents in the roof. Use a baffle to keep the space you created free of insulation. You will find baffles at any of the big box stores.
The mold may or may not be caused by the the lack of ventilation in the attic. Condensation occurs when a surface is colder than the air around it, and any moisture in the air will condense on the surface as on a glass of cold water. If the insulation is thin in the attic, condensation may occur in kitchen and bathroom areas in the winter months. Installing the right amount of insulation should provide the proper thermal break to stop this problem.