Cate Blanchett isn't who I'd expect for Lilith, but I can see her making it work. There's an overlap in personality between Jack Black and Claptrap, but he's not quite the right actor for it, because he's too Jack Black. Took me a while to realise JLC was meant to be Tannis. Kevin Hart is downright goofy and not remotely suitable for a straight man role. Can't really speak for Ariana Greenblatt as an actor, but she doesn't seem wild enough for Tiny Tina in the trailer. For all of them you see the actor rather than the character.

Honestly the only one that worked immediately is whoever's playing Kreig. Looks perfect.