Perhaps what you are really finding annoying and time consuming is the transport of goods/books/reps/ships around the map? Perhaps a better solution than supercharging speed would be the ability to hire some AI (for a fee) to transport the goods for you. Maybe pay a bit more to transport with AI escort. Goods would be placed on AI transport and arrive some time later, if the AI makes it to the destination without being engaged/sunk/pirated by a player. This would add content and targets, as well as removing boring, time consuming tasks away from valuable gameplay time.