I painted our master bedroom about a year ago and i am now doing some touch ups. The paint I used was a flat water based green. When I opened up the left over paint can there was about one tenth of a galloon can left. However the paint was very thick. Don't get me wrong the top was on tight and the paint was NOT getting hard, but it was very thick. Is it possible to add water and thin it out without changing the color too much. What other options do I have. I would rather not buy a new can of paint just for a few touch ups.

I recently painted a small night stand. It was wood and painted white. i sanded it, put on 2 coats of primer--Kilz 2, and two coats of latex satin paint. i allowed 24 hours and sometimes more for drying time for each coat. here is my problem: I set candles , pictures in frames and a mirror on top of the nightstand only to discover that when i removed them to dust a week later the paint stuck to the bottom of the mirror, candles and picture frames. I had allowed the last coat to dry for at least a week before i set anything on it. I have the same experience with an old wooden kitchen table that I recently painted. Can anyone tell me what is going on? The paint has pulled off all four layers.