The dethatcher will work fine for removing debree and clearing to soil surface for better seed to soil contact, but don't expect to use it to slit seed, it will tear the seed up and if you try to drop it low enough to till the soil, you'll break the rines which gets very expensive. Best route after RoundUp proceedure you discribed: 1. Scalp the lawn (as low as you can set your mower without hitting dirt) 2. Rake or power rake to remove debree and expose the soil for seed/soil contact. 3.Seed. 4. Spred a starter fertilizer at a rate of 1# phosphorous per 1000 sq ft. ( or per starter fertilizer bag recommended spreader setting. 5. Topdress (no more than 1/4" thick. (recommend you use peat moss--one 3-4 cu ft bag will cover about 500 sq ft or more--make sure peat moss is dry when you buy it or let it dry on a tarp in the garage--use a dust pan to slowly sprinkle it on turf, you get the hang of it quickly so that you are spreading 1/4" consistently) 6.MOST IMPORTANT; Water the peat moss untill it breaks hydrophobia and accepts water, thenkeep soil moist, not wet--water 3-4 times a day for about 5 - ten minutes each time--do not water until it pools. 7. Once seed germinates (good germination), water 2 times a day for half and hour. About a week later you can drop to watering about 3 times a week (depending on weather) and after the first mow, go to once a week for an inch of water.

Don’t listen to your pool guy. Check my post (below). We did a similar project last year. Pool is not difficult to maintain. You need to have sprinklers all around (important) as when you have a heat wave like we had in NYC a few weeks ago, the grass around the pool will die if you don’t have proper irrigation and if the water doesn’t reach up to the copping. https://www.houzz.com/discussions/6434729/where-should-top-soil-stop-around-coping-of-inground-pool

We kept all of our soil (sort of) from an 850 sq. foot excavation. I don't know what the regulations are in your area, but since you are from the state of Oregon--I am going to assume you have some lofty (or lefty) over-regulation going on in the state with regard to soil transfer & movement. This can cause costs to your builder or landscaper to have the soil tested and then sent to a state or local approved location for a fee. Expect delays if this is the case. Again--I'm assuming you can't get away with just dumping it at a local farm site, etc. even if you have a lot of "nowhere" in your area without your contractor risking being fined. This is pretty much like the regulations we have in our part of the state although things are a lot "looser" elsewhere in neighboring counties or states. Here's what we did. First, when the topsoil was removed from the dig there we were able to haul this smaller amount ourselves by truck loads to be used on a neighboring property where they wanted to build a berm. (Shush . . .) Also, we had a LOT of rocks (maybe as much as 20%) in our soil of various sizes. We used the larger ones to build several different rock walls and incorporated them into the naturalized landscaping. I refused to buy the $6K worth of rocks as estimated on our plan just to get news ones hauled in by a landscaper. You can't plant a bulb with out hitting the free ones we have around here! The walls were not really stacked rock walls for the most part, but natural boulder walls using the excavated larger rocks --some moved by machine others small enough to place by hand with one or two people doing the work. We worked around the sizes and shapes that nature and circumstances gave us. This also eliminated the need for concrete retaining block-type walls anywhere in the yard (so we didn't have to buy additional material. We also planned to have the pool set-up just slightly above the highest level of the grade and even just a few inches used up quite a bit of soil around the pool for the base under the pavers and what will be the surrounding planting beds. Lastly, we also had a yard that sloped quite a bit in several areas. The remaining soil was used to even the grade without affecting the good drainage slope--which would have set off more alarms for regulatory concerns! And now, it's all gone! In fact, we actually have had to buy good rich topsoil to put on top to do our landscape planting and to seed for grass. We couldn't have used our own topsoil as easily since it was better suited for a berm than for spreading with all the grass and such mixed-in after it was ripped-up for the dig. Also, we needed it gone before we had machines moving rocks around and doing the grading of the more compacted soil underneath. Check-into your own local regulations and don't assume your pool builder or landscaper will know if they don't do a lot of work in your town. This approach may not work for you or meet your esthetic preference, but maybe some of the ideas will apply. Good luck with your planning.

PK, I pulled it up as soon as I saw the first leaves emerge. When I pull up an invasive, I don't merely tug and yank, I get my hand weeder (or shovel) and go down deep to get the roots. Merely pulling the plant up usually leaves too much root behind. Even in places where I could not get rid of every bit of root, I just made sure that I cut off every leaf that sprouted, which insured the death of the plant trying to emerge. Diligently removing emerging foliage on pesky invasives (such as alstromeria) worked well for me because the little brittle roots were impossible to dig up. Molly