There should be some default stats for people who haven't played the first part or otherwise lost access to save files from it, but otherwise I'd prefer everything carry over. If you underlevel in the first part it might be nice to have it boost you to default stats as a minimum but it should still carry over your inventory and such (would be great if that's optional for people who want to be underleveled, but that's not me so it's not a major concern for me).