Gorgeous dress, Celia! Isn't it frustrating when colours don't transfer well? But this looks beautiful, no matter what shade of red!
Re the length: I think it works, but why not pin it a couple of places and snap pics so you can see what you prefer? Sometimes an inch either way can make a big difference to how we feel in something. I am not sure how tall you are, but for me, my own LB sheath dress felt best a bit above my knee, rather than below. Something about the slim shape seemed to like the slightly shorter length; it is still knee length but on the above-the-knee rather than just below, as this one is on you. But for you it might be different.
#2 I do think it will work with these booties, which look like a great colour for it. I think I would prefer it with tights, maybe a colour from the scarf? And I might prefer the scarf tied so it doesn't hang quite as far below the jacket. Those are beautiful colours in that scarf, BTW! Great pairing.
#3 Is that the jacket that Sveta also has? Very cool! I wish I could see your head in this shot because I bet your hair does bookend the dark bottom; as is (without your head) I keep wanting a shot of something darker up top. But IRL I think your hair probably does it, so maybe a simple pendant? You could do a scarf here, too, of course.
What a wonderful find; I think you will have fun wearing it all these ways and many more.
