Just thought it was worth mentioning how another game has dealt with this problem. Anarchy Online has static quests, like in CF, which people camp for items. However, for levelling, often a "random quest generator" is used, which is a terminal which issues a random quest, with random maps, and a random boss dropping random arches at the end. This is very similar to random maps apart from the boss. What slows players down is the need for a party to complete the quest (you need around 5-6 people to kill the monsters in there), and the quest is generated specifically for you level. Also maps have "instances". There is more than one of each map, so instead of entering (and resetting the reset timer on a map) a completed map a player may enter a new instance, which is not completed by anyone yet. Not sure if any of those are appropriate for CF though.