well i dont think the age has any effect. both my keets have very few lines.. which are all really faded, and both of them are nice.. but the older one, still is considering me. it seems like ur keet might have been mistreated earlier on in his life, so he might be a little shaky, but its all right. and wat i mean about spending time is to like, first try to touch his beak. try to get him to chew on ur finger. if he's use to ur finger. try to pet his belly very softly. u said he runs away from ur hand, well if he runs away, dont move ur hand. if he sees ur not moving, he'll calm down and give u a chance. if he gets off of the cage bars, and sits somewhere, very slowly start to advance. if he runs away, back off, and if he lands again on a perch, slowly advance again. the bird wont eat from ur hand until its use to chewing on ur finger. and will never sit on ur finger, if he doesnt trust u enough to eat from. read lisa's guide about toys. put up an almond string toy. if the keet sees u do it.. it'll trust u better.

=) i hope that helps!