If I am understanding you, it all sounds like it can be done - but a structural engineer would make the final determination. I think you will enjoy having the spaces opened. Obviously it affects ceilings, flooring, wiring, hvac and lots of other stuff so it is not a cheap process. We are in process of opening up a 1950's ranch and there is a lot to it. I don't have any pictures yet, but it certainly has made a difference in the flow of the house, improved lighting in the main section of the house and updated the look.

Like Brickwood Builders mentioned, a structural engineer would definitely be needed to make sure all that is doable but they're fantastic ideas if so. The space already looks pretty sizeable, so once it's more open concept it will have a really dramatic effect. A paint job with a lighter colour all around will do wonders to expanding the space too.

As you start planning your ambitious list of projects, you should develop a budget and a time frame for each project. As suggested by others, a structural engineer may be needed if you plan to remove walls. Since the house is empty, I am guessing you have not moved in yet. Often, you need to use the kitchen for a while to know if it needs some changes. If you save the alteration of the kitchen wall (to give access to the planned dining room) until you have lived there at least six months, you may decide you need most of the wall for additional kitchen storage and only need a framed opening between the kitchen and dining room. The open area between the entry hall and the main kitchen area will be a perfect spot for casual family meals.
Another thing I would encourage you to work on would be a color scheme of two to four complementary colors for the attached areas I see: entry, kitchen and breakfast area, living room and future dining room. If you want to paint all those areas' walls the same color, that works, too, as long as that color is not gray. One gray room, maybe, but not all of them.

thanks for your comments. I will certainly have a structural engineer look at the house prior to officially knocking down walls. Felizlady, you make a great point about using the kitchen first. I do not plan to move in until all renovations are complete. However, I may need to try to stage the kitchen and make a meal or two to see how my proposed layout would work in action.

Can you post a floorplan instead of pictures, too hard for this simple mind to follow.

I have to draw out the floor plan...I'll try over the weekend.

In the meantime, this is what happens on a rainy day. I will need a supporting beam and three columns before we can expose the staircase.

What's downstairs? Unless it is heated and conditioned space (i.e. not a basement) I would be leary of opening up the stairwell which, when open, will become an air shaft... good if you live in a hot place with low heating costs not so good if you live in a northern climate... If you are looking for more light into the lower area but don't want to open it up structurally, I have seen interior windows and/or sandblasted glass work well.