[I feel like I need to parse that one paragraph blob in a word processing app just to decode its content. Only having read it thrice, I'll limit my comments for now to hood construction and general requirements.] In order to obtain relatively equal flow through the filter area, whether baffles or mesh, there has to either be some height above the baffles (probably commensurate with their airfoil length), or similarly above the mesh (narrow dimension), or the mesh has to be so restrictive that it chokes the flow equally at all points (not good). So of all the noted configurations that weren't already rejected by the OP, I would vote for narrowing her consideration to whichever ones provide enough height for the selected filter type and dimensions. Baffles have advantages over mesh filters, but both can filter if the meshes are kept clean. Less tortuous duct paths are preferred over more tortuous paths. Full power actual flow rate (CFM) should be roughly 90 cfm/sq. foot of hood aperture, if possible. A rated capability of the blower of 1.5x that above should accommodate pressure losses in ducting, hood, filters, transitions, and MUA restrictions. Duct area should allow the air velocity in the duct at full power (90 cfm/sq. ft times the aperture area in square feet divided by the duct area in square feet) to be between 1000 and 2000 feet per minute. Aim toward the lower value if all the ducting remains warm in winter, or the higher value if passing through a cold attic. kas

I don't know that I agree that the contractor just picking a semi-arbitrary number in the range suggested for the installation is off the hook. BTW, Best by Broan also tells you how to figure the requirements for installing higher and other variations. Back to the contractor -- this is the guy who has to make sure things fit, right? You are 5'6" and DH 5'8". He wants to put the front of that hood at 5'2". He doesn't ask you how you feel about having the hood 4" below the top of your head -- or more if you are wearing shoes? He doesn't ask DH if he's going to cook and if he's okay with a hood 6" below the top of his head -- 7 or 8" if he's in shoes? So it's all your fault? You do need to specify what you want, but I think that every designer and contractor should ask about your needs and preferences -- and they must ask, IMO, if they are going to do something that is not a customary and usual standard. Not that I'm an expert, but it seems that 30" is the most standard height. I had to do my research to get something higher.

We have a microwave that has a fan that doesn't vent to the outside. At the time we built our house, they said that it was too high a ceiling to vent it out on our inside wall. We have since replaced the microwave a couple of times with ones with a filter that circulates back into the house. We don't fry much, so we don't have much of a problem and it works fine. I think this is ours. We had GE that we liked, but the magnetron ???? kept breaking. It was more to fix it than to buy a new one. Here is a link that might be useful: Whirlpool

partigal, I'm not sure it matters since switching to it would require a new cabinet at this point and I don't know that we can/will do that. But I have owned this hood previously and I was able to turn the lights on and off separately. So unless that has changed with a new model, yes it does. Additionally the lights in the imperial do aim straight down, not forward. Again, not sure it matters for me at this point though. I have actually never before seen a vent hood that you couldn't turn the lights off and on separately from the vent and I have also never before seen a hood that has lights aimed forward. And I have lived in a lot of houses. So it seems likely to me that almost any hood would be an improvement in this regard.