Cate Blanchett seems a little old for Lilith but she's amazing in everything so I think I can excuse it. But it's hard to imagine her and Kevin Hart having a romantic relationship.
I know Kevin Hart is extremely miscast for a Borderlands 2 Roland but as someone who also enjoys Borderlands 1 a lot if not more, Hart actually fits how Roland was in that game. He didn't get all stoic until 2. In 1, his lines were like Will Smith: "Boom! Headhsot!", "Ah ya, that was all me." and stuff like that. Physically he's way smaller than Roland, though no matter how you slice it.
I don't know who they have as Handsome Jack yet but I have a feeling the movie will depend a lot on that performance.