In terms of protecting the vehicle finish, both the Rhino-Rack and Thule systems install by using specially designed clips to fit the vehicle and the towers rest on pads. As long as the bottoms of the pads and the vehicle roof are clean when installing, you should not have a problem with the finish on the vehicle.
Both systems also will be about the same in terms of installing and removing. You will have to do some careful measuring when you first install the systems. After that removing... view full answer...
For the 2007 Nissan Maxima, the only trailer hitches available are class I hitches. I recommend the Curt Class 1 Hitch # C11264. I have included links to the installation details and a video showing a typical installation for you to view.
Since a class I trailer hitch is what is available for your Maxima, you will need a bike rack compatible with class I hitches. Also, on class I hitches, you will be limited to carrying 2 bikes.
In terms of weight, the Kuat Alpha, # B202-114, will be... view full answer...