Here's my Rangecraft mounted 29" from my rangetop grates (about 30.25" from counter). It's 24" deep and 42" wide. It's hard to get a photo in my space that shows how it covered the front burners. The outside edge of the vent just barely covers front burner. I'm 5' 7.5" tall. DH is 6'. The only time I've hit the hood is when I'm wearing my extra tall cooking shoes, which I don't do often, and have my hair piled on my head in a big banana clip. Under these circumstances when I approach the rangetop from the corner of the hood, I sometimes hit my clip on the hood. My clip, not my head. If I approach straight on even in my tallest cooking shoes with big hair clip, I've never hit the hood. I don't recall DH ever hitting his head, nor do I recall anyone else in my kitchen hitting theirs. I wish the front interior of the hood covered the front burners. As it is now, I cook my smelliest, greasiest, smokiest stuff on the back center burner for better capture. If I try to do that on the front burners, some of the effluent still escapes the front of the hood because the capture part of the hood doesn't completely cover the burner. I remember reading that thread you linked when I was researching hoods. That was one of very few I read where people complained of hitting their head. From what I've read here over four years, most people don't have an issue with head banging.

We have 15" deep uppers on one side of our Kitchen with standard depth base cabinets (24"D) and counters (~25.5"D) - we have no issues and I don't notice them when I'm working in front of them - and we're a tall family (I'm 5'10" - the shortest!) We have 12" deep uppers on the other side of the Kitchen and I wish we had gone with 15" deep on that side as well! I work primarily on the side with the 15" deep uppers (our Prep & Cooking Zones). Regarding the depth - it should be 18" from the bottom of the light rail to the finished counter so standard small appliances will fit under the upper cabinets. Most countertop small appliances (mixers, coffeemakers, etc.) are designed to fit with an 18" backsplash. If you want to go higher, consider whether you can reach the cabinets (as was mentioned earlier). I probably wouldn't go much higher if you plan to sell in a short time. Lily'sMom - IKEA uses a rail system for mounting cabinets.

Counter depth will stick out around 6” from the surround. You may need an actual built in. And you need a 30” cabinet with fillers. Or to use a cabinet line that has 33” cabinets. Like pretty much the whole world of cabinetry outside of IKEA and cheepchinesecrapola.

We use 2 of the HALLBAR 9 gallons in our 18" pull out cabinet and they work great for us. We don't use the lids. We do have a drawer divider in that helps keep them from moving around. We also have a small inner drawer above where we keep the extra bags. We use Simple Human liners, which are nice because they're flat packed and fit nicely in the inner drawer. Both cans fit fine back to front and still leave space for the UTRUSTA opener, which I love and recommend. I'm sure there are more perfect "hacked" options (like the person that made their own out of laundry hampers) but I a) don't have the time/energy to search/do all that and b) they looked, well, "hacked" and kinda cheap/cheesy.