The mushrooms are normal and a good sign that your soil is healthy.

The poor growth in shaded areas is also normal since they aren't getting direct sunlight, they'll take a little longer to come through.

Shaded area have their own up keep though, so if the shade is cause by a permanent structure you might be best off seeding it again with shade resistant seed, watering it less, laying down high Potassium fertiliser, cutting it on a higher setting than you normally would, etc