You asked for advice and here is mine: Modern building codes (and most old ones) require "emergency escape and rescue" openings from ALL sleeping rooms and habitable basements. All window manufacturers have a mark in their catalogs next to the windows that meet the most common requirement. Ground floor openings are allowed to be slightly smaller but it doesn't always translate into a smaller window size. The internet can be highly unreliable for code information because most codes are copyrighted and they also change every three years so you need to buy a copy of the version of the code used in your area and get any modifications from the local building department. As the property owner you will be responsible for meeting the building code and because you will not be using a licensed design professional to assure you of code compliance, you should not rely on any code information from anyone that you haven't personally verified in your copy of the code book. Please take this advice seriously. The next step is to find the window inside sash size from the rough opening size by subtracting about 3" from the RO height and 2" from the RO width. Obviously, you will not be able to use your narrow window concept for at least one window in each bedroom. Your designer will be able to help you modify the house design to accommodate this fact. I strongly recommend giving up the idea of aligning door and window heads unless, of course, they align by chance. Windows should be as high as possible in a wall to bring light deeper into a room. Never let standard door heights dictate where windows are placed; they serve entirely different purposes. Get the windows as high as you can. If a 4" head misalignment bothers you then use 7 ft doors. In old homes both grand and humble this was never an issue. I would recommend a 3-0 x 5-1 RO window with a sash opening of 2-10 x 4-10. The interior stool trim would be 2-2 high with 1-0 of wall above the window. The head opening would be 7-0 high (an excellent height IMHO) and enough above a 6-8 door head to look fine or you could use 7-0 doors. The only other choice would be a 2" wider window that is 4" shorter. I would raise the stool 4" to 2-6 (table height) for increased privacy and keep the window head the same for maximum light. Of course, you could align the doors and windows and keep the stool height at 2-2. Frankly, I would consider a window with a 30 glass width normal rather than "gargantuan". You might find a code compliant casement with a RO width of 2-4 wide. The hardware on some casement windows does not meet the building code emergency escape requirement so you sometimes have to specify the appropriate hardware option. I would take a look at it before ordering it. If you prefer the appearance of narrow windows I suspect you should be using casements anyway.

Even if the deck hatch works fine at the beginning, it will be a potential (and likely) source of frustration (or disaster) later, on account of mechanical failure, or someone leaving something heavy on it. Mechanical things that don't get used often tend to get cranky or stuck, like so many unused emergency brakes on old cars. It would be a pain to maintain such a hatch over the course of years. Personally, I'm sour on the idea of placing french doors at the end/side of house. Where do they lead to but a skinny "hall" to begin with, since there is limited space at that side of the house? And is the "view" over there? That might be one of the reasons to have french doors to begin with. I wish it were otherwise but I think your best solution may be to relocate the basement access, and possibly "revise" it at the new location. Doing it in a different and less expensive way may work as a fire escape, but not if the access is needed for common utility purpose, like carrying out a load of laundry. One must view such projects in light of the total value of the house. Sometimes, if corners are cut the wrong way, the house is devalued. It may show up as immediate dissatisfaction and "having to live with" something one doesn't like, or later as a monetary devaluing of the house market price. Usually, if it's the former, it's the latter, too. It would be better to create something that not only doesn't devalue the property, but adds value for the present and future user, even if it costs more up front.

R310.1 Emergency Escape And Rescue Required. Basements. habitable attics and every sleeping room shall have at least one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, emergency egress and rescue openings shall be required in each sleeping room. Where emergency escape and rescue openings are provided they shall have a sill height of not more than 44 inches (1118 mm) measured from the finished floor to the bottom of the clear opening. Where a door opening having a threshold below the adjacent ground elevation serves as an emergency escape and rescue opening and is provided with a bulkhead enclosure, the bulkhead enclosure shall comply with Section R310.3. The net clear opening dimensions required by this section shall be obtained by the normal operation of the emergency escape and rescue opening from the inside. Emergency escape and rescue openings with a finished sill height below the adjacent ground elevation shall be provided with a window well in accordance with Section R310.2. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court that opens to a public way. Exception: Basements used only to house mechanical equipment and not exceeding the total floor area of 200 square feet (18.58 m2). R310.1.1 Minimum Opening Area. All emergency escape and rescue openings shall have a minimum net clear opening of 5.7 square feet (0.530 m2). Exception: Grade floor openings shall have a minimum net clear opening of 5 square feet (0.465 m2). R310.1.2 Minimum Opening Height. The minimum net clear opening height shall be 24 inches (610 mm). R310.1.3 Minimum Opening Width. The minimum net clear opening width shall be 20 inches (508 mm).

I think a tapered boxing would look better, assuming that the stairs rise over the kitchen. It's just too top heavy and the tapered boxing (with the front plane a right angle triangle) would give it some room to breathe. You can put some blue tape in the projected possible line of taper over the current box to try to visualize it.