You need to do a little more archeological digging still. You need to know the whole construction of the floor before you can decide how best to install something new. I'd take up that plywood piece in the kitchen and see what's under it. It's higher than the surrounding floor, so needs to go. You should also be able to see from there what subfloor is under the original kitchen hardwood. It's too bad the space under your entryway is finished, but I'd still do some exploring from below to see what's under there, and to figure out the fix to stop it from squeaking. Is it drywall below or a drop ceiling? I know it probably seems like a pain to tear out drywall, but if you cut out a clean patch, like 2' x the width of the joists, it'll be relatively simple to repair. Just make sure to cut it down the center of the joists so that there's room to screw the patch piece to it later. Cut the hole under the area that squeaks the most, if you can. Have someone walk on and watch the floor from below to see what's moving. It might be as simple as pounding in a couple shims from below, or face-nailing a loose board from above. You want to find out what's underneath the hardwood. It might be laid directly on the floor joists, or there might be 10" wide boards that the hardwood is nailed to. Another thought is to take out a board in the hallway, since that's not original and you want to replace it. See what the subfloor is there. I am a bit puzzled at why, when you've stripped the kitchen down to the original hardwood, it's still higher than the hallway floor. Is your current surface perhaps not the original kitchen hardwood? Peeling back the plywood area will help determine that. BTW, I haven't heard of that stop squeaking product you linked to, so can't offer any personal opinion. And don't pour self-leveling compound over top of hardwood. It needs to go over plywood.

I'm a fan of Hickory. Love it! I love it's STRONG variation! Yep. Variation is the word that can be used for Hickory. If you are going for "mid-tone" then it means the Hickory is stained. No problem. That's fine. Hickory takes a stain very nicely. But it will still have plenty of variation. The stain will even that out a little bit, but not entirely. The finish is UV cured urethane. I'm not very excited about that finish. If you are going for factory finish, you will want to work with the TOUGHEST finishes on the market (that's why you go with factory finished...for the TOUGH finish). The UV cured urethane is a ho-hum type of finish. Average would be the best way to describe it. The thickness of the plank is 3/4" = normal for sold. The plank width is 5" with random lengths UPTO 60" (5ft). That tells me there will be many planks in the 3' - 4' range. Again, this is ho-hum average. And with a wide plank product, it will need "glue assist". And Hickory certainly needs it because it has a bit more movement (less stable) than white oak. And then there is the "low gloss" format. The low-gloss finish on this depth of colour = nightmare to live with. It will show dust, etc as well as oily foot prints, sock prints, paw prints and will look hazy at certain times during the day. The "haze" is part of the chemical make up of the finish itself = that's how they take away the gloss...they haze it with a chemical additive. The haze goes away when you sand and refinish the floor. That's the only way to fix it. If you must have a mid-tone floor, I would recommend a TOUGHER finish (aluminum oxide or ceramic infused polyurethane) in a satin. Satin is FAR MORE livable. It offers a lovely glow without being shiny. It hides skin oils (like paw prints from dogs) because it is the same gloss level as skin oils....it isn't hazy....you get the idea.

The warranty information explains EVERYTHING...which is to say...it is almost identical to regular engineered hardwood and/or vinyl planks: 70d364c8-88d9-49d5-b701-8f2bc5202730.pdf (homedepot-static.com) Check out page 3 of the Warranty: Exclusions from warranty coverage: Water damage caused by flooding, prolonged stay of standing water, subfloor hydrostatic pressure (water or moisture under the floor that is transmitted to the surface through exerted pressure), leaking pipes, household mechanical failures, appliance leaks, door and window leaks, or conditions that result in moisture being below the floor are not covered. • Water damages to the surrounding areas attached to the flooring. The flooring itself is waterproof, but it is not a waterproofing agent for other objects. • Gapping that are less than less than 10 mils wide and less than 2 inches long. • Separation between layers caused by exposure to excessive humidity or temperature and environmental changes that occurs during or after the flooring has been installed. What this tells me is: the floor isn't water proof. The CORE is water proof but the wood ON TOP is not. Wood is NOT water proof. It never has been...and as far as today's technology...it never will be. The one and only wood that is IMPERVIOUS to water: 100% cork tiles (glue down) that is site finished. That's it. That's all. You are being sold a bill of goods that won't hold up to homeowner expectations.

Thanks. My biggest concern is the kitchen cabinets. The floor would be 1/8” shorter so I’m worried about 1/8” exposure that was never there before at the bottom of my cabinets. That may look terrible considering I just restained them and they sit on tile. Or, is there a way that installers can raise the edges 1/8” in those places (where the floor meets the cabinets)? I honestly have no idea how this would work and the installer wasn’t too clear with me. Two of them said it would work though. One was via email (not too responsive so it’s hard to get a straight answer) and the other didn’t have an answer I understood.