Week 6 comment: the bat guano should have enough nitrogen to bring back the color. You can continue with nitrogen supply for the next 2 weeks tops, then you should switch to "bloom" nutrients only.
The brown spots are insect bites. Try neem extract or yellow sticky strips. And , in my experience, you changed to "bloom"nutrients too soon, as the plant still needs more nitrogen than potassium. You can go back to "grow" formula without flushing if it´s the same brand, for at least a solid week, than half/half (grow/bloom) for 3 or 4 feedings, than bloom for the rest of the period.