Your dead spots look like dead or dormant annual rye grass to me. In Iowa rye grass both annual and perennial grow very nicely in May thru July. But often it goes dormant or dies out in August. I've been over seeding my Iowa lawn each year with about 50% Tall Turf Fescue and 50% Kentucky Blue Grass The TTF is used in the sunny areas and the KBG in the shadier spots under my trees. Crab grass (aka) water grass in Iowa is easy to spot ... it looks like this. To kill it use Trimec or 2-4D on it. Halts will work to help prevent it's spreading but, you can not over seed when halts in on the ground. As it will prevent the good grass from germinating too.

"BTW - history completely contradicts your belief in soil testing. Almost nobody gets soil tests now and they weren't even available to homeowners until recently. Like a lot of modern technology, it can be a useful tool. However, people got along just fine without them in the not to distant past." What does that even mean? History contradicts your belief in soil testing? How does history contradict a belief in soil testing? That sentence is an example of making up something that sounds intelligent but has no basis in fact. Soil testing is an extremely important part of all the crops growing in this country. If we had a better understanding of soil science earlier in the 20th century then the dust bowl probably wouldn't have happened, or at least it wouldn't have been so bad. Turfgrass, like any crop, has its ideal soil conditions. The closer you can get to the ideal, the healthier the grass. How would you know if you need lime? Let's say you need lime, which one would you use? What about a phosphorus deficiency. Most fertilizers have little P, so are you supposed to guess if you have deficiencies? Andy's plan is the right way to do it. Sure you can do a renovation by omitting steps, but if you want the best results you will do it the right way. Rushing it will usually result in doing it again next fall.

We're hip deep in a bathroom remodel and at the same time we are having a new boiler put in to include breaking our house into as many zones as possible. The latter is relatively stress free for us except for writing the big check but the former has been like pulling teeth since before christmas to get the plumber to do his job. He FINALLY finished roughing in the shower (the last outstanding thing) thank goodness. Remind me next time to KISS (keep it simple, stupid). Between my toto toilet and my in floor heat and my lovely towel warmer it's been... interesting. I'm not even thinking about what I'd do if we had to make a hasty exit though, yikes! I wonder if in some ways that was a self fulfilling prophecy for your neighbor. I know we'd do everything we had to do and cut everything we could to keep our house if it came to that.

We installed a similar vent-a-hood (48" with 900 cfm triple blower fan), and you will definitely need to do some work on your ceiling. We installed in a 1 story house, and we were using the vent-a-hood liner, not the stand-alone housing. They built a decorative plenum above the range (cathedral ceiling) and recessed the hood liner up into the plenum. The ducting then connected straight up to a vent through the attic and to the roof. I believe that the unit you picked is actually two 600 cfm dual fans that each require an 8 inch duct. You can then use a duct combiner (about 17" tall) to bring them together into a single 12" duct. The centerline of each 8" duct is about 11" away from the centerline of the hood. Do you plan to build any type of decorative plenum/trim above the hood to get the hood to the correct height over the range? If so, that could give you some working room for ducting options. The option I am considering is whether you could use two 8" ducts, but jog one over so you could run them between two adjacent floor joists or one above the other (hidden by a plenum). It still requires removing quite a bit of ceiling, but will fit well with typical joist spacing. The other choice is to run each 8" duct a different direction along the joist, but you will probably run into a load bearing wall in one of the directions. The other option is to look at the floor above to see if you could route the 12" duct (or two 8" ducts) vertically. If you could grab space from a closet or the corner of a room, you could run the duct(s) straight up and out the roof. The code requirement for make-up air when a fan moves more than 450 cfm is a relatively new requirement. If your city follows code, you will have an added expense for an automatic make-up air vent that opens when you run the exhaust. However, I installed a 600 cfm fan during renovation of my current house in 2014 and the inspector never even mentioned make-up air, so YMMV. Removing and replacing sheetrock ceilings is messy, and looks bad when its out, but its really very straightforward construction work that does not require a licensed professional. I would not get very concerned about how much ceiling has to come out. Bruce