Ioan Gruffudd might not be reprising his role as Harold Lowe anytime soon, but he is going to present the ITV Wales documentary on Lowe which is filming at the moment. Scenes in North Wales have already been done, and Gruffudd (whose shooting had to be delayed due to his other film committments) will be doing his segments this month.
I'd be inclined to cast unknowns in the roles of officers - I'd like to see, if possible, ages and general physical appearance adhered to, and people that (if not indigenous to the location these men originated) are at least capable of doing the regional accents. I'd also like to see hardened, non-Hollywood edge to them - even the youngest, Moody, had been at sea for almost a decade. If you've read Lubbock and other contemporary sources you know the sort of escapades they got up to.
Liam Neeson should be an Irish character - I'd cast him as James Farrell (although perhaps he's already a bit old for that role).
), but I would rather see him as James Moody, though he is just a bit shorter than James really was, but he has a sense of humor and a sparkle in his eyes that Moody must have possessed. 
