1) Scratches?
For a quick-fix touch up, use the appropriate color shoe polish on scratches, especially to make them less visible on the feet of furniture.
2) Stains?
Get rid of white hazy mug impressions by rubbing it with a mixture of non-gel toothpaste and baking soda.
3) Caution
The temperature of the summer sun coming through a window can go above 40 degrees which can destroy, fade and dry out the wood. So keep your furniture away from the sun. There surely are some outdoor furniture you can find that is not affected by sun. We at Adbhuta also make furniture with Sal wood which can withstand sun and rain.