60" is fine and actually 48" is ok depending on what/how you cook. Unless you have a french top or 24 inches of grill and/or griddle in the middle of the stove, just do your high smoke cooking on the middle burners. We were limited to 48" of width for the hood and keeping the high heat stuff in the middle works fine for us. Most people don't simultaneously do heavy sauteing on all the burners across the front of the stove. Usually one high heat pan and other pans warming vegetables or boiling water. A little steam from a boiling pot usually isn't that big a deal (compared to grease) and even a 48" hood will get most of that even on the outside burners. Just as important is the depth; should be 27" at a minimum and maybe more depending on how deep your stove is and the configuration of the underside of our hood. Front 2-3" usually is taken up be switches and lights so it doesn't help venting.

Ditto. 60" is fine even 54" is good and 48 works well too. I would call 54-60 ideal. In my case, we matched a 60" liner to a 60" range (over 60" was custom and automatically double) but built the capture area 72" wide and inset the hood about 4 inches effectively creating a capture area of 72". The capture area also extends past the front and back of the range too by about 3". Finally, we put a 2,500 CFm remote blower on it. It works great at the highest of output from the burners and believe me, those Blue Star 22K burners can put out some heavy fumes/steam.

I think the standard recommendation is 6" wider than your range, so 54" is what most stores will tell you. Our liner is a Vent a hood, don't love it, or hate it. It works, but I don't see it that much.

In the absence of any cross breezes due to open windows, air vents, or moving people, the effluent expands from the pan surface at an approximately 7-degree half angle. Thus, the bare minimum overhang is a function of hood height, burner configuration, potential air disturbances, etc.

The standard recommendation is likely for a 30-inch height above the cooking surface. That would make the overhang 11 degrees relative to the surface edge, which should be sufficient, so long as the air flow is also sufficient to ensure that the captured effluent is also contained effluent (doesn't curl over in the hood and leak back out).

kas