Hi Theresa!

The growths on the leaves are leaf galls, an abnormal swelling of plant tissue caused by insects, fungi, mites, bacteria or nematodes. Chemicals produced by the egg-laying and feeding activities cause most insect and mite galls. The chemicals cause the affected plant cells to swell. 

The white spots on your furniture could be residue from the gall-making organism (probably an insect) and similarly should be harmless. As for the second photo, it's difficult to see, but perhaps aphids caused distortion of foliage while it was expanding (and may be leaving the residue).

Good news, though - neither cause any serious health problems for trees and no control is recommended.

Jamie