I interpreted brutuses answer "paint the inside of the doorway the same color as the first room you enter" as follows: I have a family room on one side of my kitchen and a dining room on the other. Both are painted the same color. As I enter the kitchen, I would paint the inside "doorways" the same color and once you are in the kitchen, that is a different color. You could reverse that and say what about when you come out of the kitchen, but you can't come out of the kitchen without having "first" gone into it, by way of one of the other rooms. The continuity of the color stays in tact. I think that answer also means it will vary by interpretaion and individual opinion of the flow of their space. I also questioned the continued use of white baseboards/trim. The contrast of the white baseboards remind me of the way I learned to color and always outlined in black, to keep my other colors within the lines lol. I decided to use a wood stain that matches the floors. It's time to color outside the lines... :)

Thresholds are exterior and saddles are interior. Their sole purpose is to allow an undercut to be small and still have the door clear an area rug. This was the norm a hundred years ago. If you don't have area rugs or you don't mind high undercuts there is no reason to have them. If you ever have anyone in your family in a wheel chair for an extended period of time you will have to remove all of the saddles anyway. I can't think of any purpose for a saddle where there is no door unless there is a major flooring material change that was not properly worked out beforehand.

The floating wall! The floating wall! Yes, that is so much cooler than the picture I'm about to show you of... a 1980s time capsule. The plantation shutters do a good job, when closed, of hiding the euro-style cabinets. Even with the shutters closed, but the louvers opened, you couldn't see that charming detail, but it didn't seem so closed off and you could have a conversation through them. (there was a dining table and a small sideboard below the window) With the louvers closed, it was just neutral, but not a blank wall. Of course, these are the realtor pics so they were open. As for sink open to LR, that's just my preference. I like my kitchen more separated, especially the sink. I think I'd rather a window above the sink than completely open. But, that floating wall is wonderful.

Install hardwood that is continuous. Or a glue-down floor of any type. Or Ceramic/porcelain tile. A permanent floor can run through doorways without transition strips. The fact is the floating laminate floors require the T-strips. There is no way around it. Some vinyl floors can have continuous floors...but those ones are expensive AND have a maximum size allowable. The maximum runs are more for retail or commercial spaces. They don't do very well with multiple bedrooms + kitchen + den + hallways, etc.