I would go with ceramic tile if you have alot of muddy kids, or pets. I have new wood floors in my kitchen and I am now worried that it was a mistake there based on what I have seen at a few friends houses who have had the floors for a few years. Wood is not the most durable surface in a workspace. Another friend has dark blue and white checkerboard tiles in her kitchen and absolutely hates it. It shows every speck. I would get something with a more random pattern that looks like dirt! It won't show anything! I saw some beautiful porcelain tiles at Daltile that look like marble. Just beautiful and the grime would not be irritatingly noticeable. Slate might be great. It just needs more upkeep, sealing it periodically.

I am not a guru but I can give you my opinion. Melanie on the regrets - while trying to minimalize them they still will happen! Flip side is you will likely also have some grrr that ends up turning out different but BETTER than you imagine. IMO stealing the foot makes it much more functional so I would do it in a heartbeat but I am not the expert. It also opens it up and will 'feel' better. I think that's a good spot for a broom closet and charging station and should easily stay tidy. It is about 5' wide yes? That is a nice size space. Measure what you have you want to store in there and then look for pics of what you are thinking. Utility sink in the garage - really in the winter there isn't much dirt and when it's exposed it's frozen too so I'd think the utility sink would get more use in the spring summer fall when it's thawed so I'd keep it on the table too. My opinion - your money. Ha! As far as 'enough room' - it sounds like your kids are younger based solely upon still being in the 'add more' season of life. :) I can tell you only to think seasons, think sports, cleats, basketball shoes, church shoes, boots, hiking shoes, tennis shoes, flops, bats, ball caps, backpacks, lunch boxes, water bottles (if you have girls think even MORE shoes and then purses - ack)........ I will say for my 2 the space we have is more than adequate and it's quite roomy (I just double checked and it's actually 6.5' on a side so each person has 3' plus). That said we also have a closet near that I put off season stuff in and dog food. Winter coats and snow pants and boots are not in the locker area all year. I put them in the closet over spring/summer/fall. As long as you have a spot for that I think you are fine. Off season can closets can always be in the basement as well. There are always sweatshirts hanging and ball caps. Besides that there is always a stray nerf gun, goggles, flash lights and what have you hanging out there. I don't mind it there - it's out of the way and not underfoot! Old house it used to be in their rooms and all over. We had no designated space for outdoor wear anyplace besides bedrooms. If I am feeling brave I will snap a real life pic of it in action. It is easy to pick up and look presentable when needed but typically M-F it's a dumping spot. I like an open bench vs doors because we do use it to sit down to put stuff on and take stuff off regularly. And when our parents come and use that entry they love to be able to sit down to put on and remove shoes. It's comfortable and useful. With your window placement in the bathroom and the exterior door you will find it a nice light filled space. Our exterior door there is 3/4 glass and I love how it lights the hall. It is never a dark space.

Not knowing what the style of your house is, it's really hard to make a recommendation. However, a good friend installed large format, rectangular, slate-look porcelain tiles in her home and they look really good. Slate has been around forever and in my mind fits the "timeless" requisite. Hers looked very similar to this one:

I like the ideas. If you want stone, you have to have the correct joist spacing and size for that. On the John Bridge forum there is a calculator to determine the deflection of the floor system. Too much movement will crack stone yet will not be a problem for porcelain, up to a point. I have the exact set up you are talking about. I have yet to decide. I have floor thickness to consider as well as a stairway to the basement. Good luck, I will be following for ideas :)