For most of his history Balder has been just another noble supporting warrior of Thor. Supposedly he was more noble than Thor or had a different kind of nobility, but I don't think anything was ever done with this. A few storylines have developed him more by making him a love interest of Karnilla or a failure as a king. The light god angle with accompanying powers I don't think was ever fully realized.
So, what story could be done with him? What could be done with the character? Personally, I wouldn't mind a short story chronicling an untold adventure with Thor and him. It could explore that actual differences in their nobility and on how Balder got the title of "god of light." Maybe a redemption story for his failures? thoughts?
Balder's always been one of my favorites. Maybe attributing powers of truth and discernment to his light powers as in dispelling illusions and seeing alterations in reality? Eye of Agamotto kind of thing? Maybe even eventually revealing the source of this power(and the Eye) as Veritas, the embodiment of truth in the MU. Maybe written by JM DeMatteis? A story of his time in Hel by Warren Ellis would also interest me. And how about a story revealing Balder once lifted Mjolnir but never spoke of it out of humility?