I read all the reviews and Weiman's glass cook top cleaner is the winner! I use it, and it works very well. The cook top is very easy to clean. The manufacturer suggests cleaning after every use other wise the food that has spilled will be baked on the next time you turn on the burner .. so if you 're not into cleaning the top every time you use it then maybe get a conventional coil burner.
The scratches come from low end pots and pans with uneven or gritty bottoms. Use proper cookware and you won't scratch the surface. My cookware is Belgique and Gordon Ramsay Royal Doulton: the stainless steel bottoms are clean, flat and heavy. Lighter pans are easy to move / spin and that can leave scratches.
If you want to do some serious stirring just lift the pot, stir, and then place it back on the burner.
Minor changes in the way you cook at the stove will keep it looking new for a very long time.
Other hints: I bought two pretty trivets with rubber feet to sit on the stovetop so I can "land" baking sheets from the oven or other hot things without risking scratching the glass. I also use an oversize draining mat to keep the surface covered so I can use it when the burners are not on to land other items, like when I am emptying the dishwasher, etc. The mat gives me extra counter space

I had a Jenaire that was center vented to outside and now with this range I have no vent at all. It will have to be added somehow overhead in the future. Pan searing and frying bacon or fish creates quite a mess in the air that needs to be cleaned up somehow or vented outside. With nothing, the house smells for days, and kitchen will get greasy.

It's an option right on the front panel... Works very well.

The measurements are given in the specifications section when you are viewing the product online. It shows 26 3/8" for the depth but that is from the front edge of the over door handle all the way to the back edge of the glasstop....but under the back edge of the glass top is a groove for your countertop to slide into. This gives you anywhere from 1/4" overlap to nearly 2 inches of overlap on your countertop. From there you position it so the front is flush and so there are no gaps around the glass top and countertops.

The knobs are made of metal.