I would just add to the idea a MapMaking skill and a MapReading skill to the game. That way, even if you did get hold of a good map, you'd need to know how to really read it to get the full benefit.

Likewise, not many people can actually make an accurate map. In order to make a really good map, you'd need high skill. Similarly for copying, not many people can accurately copy a detailed graphic document, without having skill to do it.

A cool enhancement would be to add a screenshot journal, so that as you tag a location on your map, you could embed a screenshot too.