It just so happens most kits lenses are cheaply built, but still many have decent image quality.
The 12-40/2.8 although sold as a kit (and also individually) is arguably the best normal zoom for m43. The only other contender being the Panny 12-35/2.8 which incidentally is also sometimes sold in a kit with Panasonic bodies.
Every other m43 normal zoom is inferior in optical quality in comparison.
Christmas and New Year already over, you have bought the camera, please start a new thread for new questions.
Newbies questions on filter and lenshood