I don't think one or two feedings of it would be bad, but I wouldn't provide it as a steady diet. Its NPK numbers are 10.6:4.4:1.7, which seems a bit heavy on the nitrogen, if you want your plants to flower well. It would be fine for foliage plants, though.
I agree that your plants are probably suffering from too much water. You need to check below the surface, by digging into the soil with a fingertip. If it's really dry down to 1", then yes, water. Otherwise, I'd hold off watering as long as you're getting a lot of real rain. Here where I live, "rain" can be anything from a downpour to a light mist. If it's only misting, I'll water. If it's pouring
down, then I don't water.