Veneers would look fantastic, Invisalign may be more conservative to achieve a straighten smile (may take much longer), bonding may improve you smile however you would still need prep the teeth.My recommendations are in that order.
Assuming your implant has been properly healed in the bone, there should be no movement at all (even less than natural teeth may move).Most commonly this is because of the prosthetic crown loosening or the implant not integrating properly into the bone.Dr. Alan Jurim