Who Should Play Lisbeth Salander?

I honestly think they're all great choices, and obviously Kate Mara would be cool stunt casting, considering. But I give the edge to Imogen Poots, especially after her kick-ass performance in Green Room.

That came into mind, and I figured since they're rebooting the whole damn thing they might as well reboot Salander too. As well as being an intuitive, brainy computer geek she could also be an imposing figure with that height. Debicki has always carried a mysterious aura about her too and I think that would certainly fit into the nature of Lisbeth.

Her short height/thin frame (at least in comparison to the men around her) is supposed to give off this "big things come in small packages" misleading appearance (in combination with her gothic wardrobe, facial piercings, tattoos); it's one of the main things about her physical characterization. Making her 6'3" gives her too much of an advantage. Debecki would probably be much taller than her male costars, including the ones who attack her, so making her so tall, coupled with the character's ferocity she has even as a short version, just makes it seem unrealistic that she can't defend herself. That'd remove that fragility of her character, and make her look too intimidating. Who the hell is going to mess with a giant gothic woman?

But of course, if they retcon it, they can do whatever they want. But I'd rather they be more faithful to the source material. Or just superimpose her face on a shorter actress body or get male actors who are 6'8" and taller to offset her height 

Anyone but Rooney Mara

Definitely.
Why and how they mucked this franchise up the way they did I will never know.
I think Tatiana would slay if it came to recasting though.

If Other can just be Rooney Mara, then other.

Alicia Vikander. Either go with a Swedish actress or bust. Of the rest, I'd be quite happy with Anya Taylor-Joy as well.