No. The difference is almost too small to measure; about one part per million. Correct, sort of. The system that is Earth and Moon orbit the Sun at the same speed. Since the center of rotation of that system is not the center of mass of the Earth, then there's a little increase and decrease of orbital speed as measured from the Earth. Again, almost too small to measure. There are over 4000 man made satellites orbiting the Earth. None of them "stopped." (Other than the ones that re-entered, of course.) The Earth is gradually slowing down due, in part, to the attraction of the Moon on the sea and air. Eventually it will stop and become tidally locked to the Moon. Estimates for this are in the ten billion year range. So no worries in the near term. Matt Jaffe and Holger Muller of UC Berkeley have in fact measured the effect of the Moon's tidal acceleration on free particles. Here is some data for you: When the Moon is overhead you feel 9.79999883 m/s^2 of gravity. When the Moon is beneath you you feel 9.80000111 m/2^2 of gravity. (Assuming you are in a place where the normal acceleration is 9.8 m/2^2.) Do you feel better now that you have the data?