I think he knows a lot more about the future than he lets on, however I think he withholds certain information, cautiously, because if he told someone everything then that persons knowledge of the future may change the future. For example if he told angel he was going to win a fight or something then angel would go into the fight expecting to win which means he'll be a bit cokcy and fight differently, which could actually lead to him losing the fight, whereas if lorne simply tells him where the fight is then he wont really fight differently, if you know what i mean, except yopu probably dont because i didnt really articulate this very well lol