Could you take a picture of what's to the left? Are you trying to make this a living area or just a more functional entry way?

A functional living space, thanks!

Wow, this is challenging but I love solving problems like this!

Slate floor: I had a slate floor once upon a time, same issues. You need to clean it and seal it according to what's appropriate for a slate floor. Sealing is the key to keeping it clean.

Wallpaper: you can paint wallpaper. You will need to test it to make sure it won't bubble. See instructions on bejane.com. Ask the folks at Home Depot or Lowes for correct primer to use.

Entry way (area in front of wood stove): take everything out and start fresh.

Paint #1: I would paint the walls a deep version of what's in the floor either green or blue. Go get some paint strips that have your floor colors. Do the best you can from memory. Bring them home and match to the floor as best you can. Now go down the strip to the last or second to the last color. Don't panic that this will make the room dark. What's going to make this work is painting the trim and door white and getting some better lighting and some other things. Now we have bridged the floors and the walls and honestly it will probably make the room feel larger. Keeps existing blinds.

Paint #2: If all that is out of your comfort zone, then go up the strip to the second or third color, just not the lightest. Trim and door would remain stained. Consider replacing your blinds with matchstick blinds in a natural color.

Paint your entry door red either to match the stove or the red in your floor. If you want some privacy, you can get frosted vinyl to put on the windows of the front & back doors. They have it at most hardware stores.

I like the idea of storage trunks under the windows but with a slight change. Get wood ones in a natural wood finish. Or if you can find one to match the other one that would work too.

I would replace the tall storage cabinet with a hall tree in the natural wood color. I would put it where the tall cabinet is now but on the angle toward the door.

Get a half round entrance mats in a beige tone that matches the natural wood color for both doors.

I like the color of your sofa but I think it too big and bulky for the space.

If you could get something smaller, it would allow for an end table and lamp and I would get an ottoman. I have a couple of other ideas but I would need some measurements.

No here's something out of the box. If you don't use the wood stove, how about putting a small TV on it. You can make your tv a smart tv which is wireless using the Internet.

Lastly, window panels for all of the windows and some accessories.

I know this is a lot. You can do a little at a time. If any of this sounds like a plan, I will put some color/idea boards together so you can see what's in my head!

Blessings!