A character who can max out Diplomacy, Bluff, Sense Motive, a Knowledge skill or two, Use Magic Device, Perform (various), Gather Information and Spot (not a class skill, but you could change that - maybe every skill shoudl be a class skill) and Listen would be awesome indeed.
His speciality would not be combat, but combat avoidance though early detection (Spot and Listen) and negotiaion (Diplomcay, Bluff and Sense Motive) and maybe Tumble to stay out of the way.
He could also use his Knowledge skills to let the party know about the weaknesses of whet they are facing, and Bardic Music to buff up the party for combat.
This has a lot of potential, but may not be your style.