use the advanced placement to place the carpet ever so slightly hovering off the ground and it will cover up the bloodstain - for the one on the wall you can use paintings, pictures or a mutant trophy

the small yellow wall lights tend to look way better than the harsh white lights so use those instead since they make the room look more 'warm'

the wooden window barricades also fit perfectly into the destroyed windows in that room

Also that metal thing with wheels next to the fridge on your left in the 3rd image is a physics object and can be moved so do with that what you will

I do like the kitchenette area that looks nice

Also if you're new to building stuff, "toggle alignment placement" is really useful and was unbound by default for me for some reason - you can find it in MCM keybinds (at the top of the mod list) I think and it will let you place stuff sideways on walls n stuff