Cleaning Hard Water Spots on Windows?
I am not sure using CLR would be good for the environment, but as long as you keep it off the ground and wear gloves so you are protected... I can also suggest a razor blade to remove any remaining film/crust from hard water stains.
Getting Rid of Mushrooms in Lawn?
Generally, aerate and dry out the area. Remove branches that shade it, the source of the fungus growth, and reduce water levels. More here: http://www.ehow.com/how_5327466_rid-certain-area-rest-summer.html
Tiny Flying Insects in the House?
What I believe you encountered is a Thrips. A Thrips (yes, it is spelled plural) of the order Thysanoptera is small enough (less than 1/20 inch long) to crawl through the mesh of a window screen or some camping-tent mesh. The bite of this insect feels similar...
