Is it safe to assume that the silence from the forum means that my plan makes sense and is on track? :D Was really hoping to hear from someone! :)

I agree the first weed looks like bermuda. That would not surprise me in your area. It is probably fairly weak in the shade and that far north, but during a summer like this one, it would take advantage of any weak spots in the yard. Since you have both bermuda and crabgrass, you must get plenty of sunlight - hard to see on the cloudy day. Still, cloudy day pix are 10x better than sunny day pix, so good for you. Weeds are normally only a problem in weak turf, mowed too low, with too frequent a watering schedule (or rainfall). Nutgrass is a swamp grass. Is yours growing in an area that gets a lot of standing water or runoff? If not then it is possible you have an underground bucket that tends to hold water longer right there. Perhaps it was scooped out by a rototiller or some other device. Get your soil softened and that should clear up. Softening should not be done with an aerator. The results will not be what you are looking for. For the past year I have been really happy using clear shampoo at a rate of at least 3 ounces per 1,000 square feet. Spray that down, irrigate a full inch, and repeat in 2 weeks. Your soil should then be soft when you water it or when it rains and gradually become hard again as the days go on when you do not water. At this time of year you should be backed off to watering once every 7-10 days. By the time Thanksgiving rolls around you should be watering monthly. The really infrequent watering usually will take out the nutgrass. What kind of grass do you want to have? Here are your choices: Bermuda: takes a lot of work to keep it really nice. Needs heavy feeding monthly, mowing 2x per week, and it turns brown in the winter. It will not grow with any density if it does not get very full sunlight. Spreads fast enough to be considered a pest. Fescue: much less work to manage than bermuda. Let it grow 3-4 inches high (highest setting or nearly). Fertilize 3x per year with chemical ferts or anytime with organics. Grows from individual plants which do not spread, so if it is thin, or gets thin from drought or insects, it will remain thin until something fills in (weeds usually). Usually it needs to be overseeded every fall. Fescue is the only grass on this list that will grow in the shade. Your shade may be too much for even fescue but you can give it a try. The others will die out. Kentucky bluegrass: also much less work than bermuda. Feed 3x per year with chemical ferts or any time with organic. Mow at 3 inches. KBG will spread to fill in weak areas. KBG is often used along with fescue just in case the fescue runs into problems. KBG turns brown in the winter although it does not have to if you want to join a band of lawn nuts who have eked out a plan that keeps KBG green all year. Perennial rye: can be a great lawn but is seldom used east of the Cascade Mountains. Mow high. It does not spread so you will likely have to overseed every fall. Fertilize 3x per year. If all you want is green, then I would let the current situation go. You might even mix in some Dutch white clover. But if you want one of the regular turf grasses as a monoculture, pick one and we can help you get on track. Now is the time to act. DO NOT WAIT UNTIL SPRING to seed grass.

"The web page cannot be found" is all I get.

There is no practical way to selectively remove these various grasses as your lawn matures into what Tom Cook at Oregon State terms a "climax lawn" of a mosaic of grass species. Chemicals that would affect the target would also affect your desired variety. You'll have to start with a clean slate if you want that even look. The link is to an excellent document that covers quite a bit about Northwest turf. Here is a link that might be useful: OSU extension