Isn't he too old to play Omega Red?
No, he's only 56, and they will have less work with makeup. 50+ guy should play this Russian zombie. Dolph would do good job like as Ivan Drago.
Liev? It's prequel, not sequel?
Also it should be in new reality, so I doubt there will be Yukio, but who knows what new future after 1973 brings.