The first issue is beyond me, sorry, but it sounds like a good place for a daemon and is probably mudlib specific.
The second issue isn't. In the heartbeat of all mobs, increase the xp value by 1. When the mud boots, they all load at the default value, but as people -don't- kill mobs, their exp value increases. Go find the default mob in your mudlib and add it in--depending on balancing, you may need something bigger or smaller than 1, and there's probably other places to put this that'll make it happen slower if you need that, but there you go. When the mob is killed and reloaded, the exp value resets and begins incrementing by 1 every heartbeat.
If you want this to save over boot or only work on specific mobs, that's slightly harder. In the first case, you probably need a daemon with all mobs and their time since last kill, in the second, just make a new base object inheriting from the default mob that implements the functionality, call it exp_mob or something, and inherit from that one for mobs that are supposed to do this.
Someone can probably provide more details--I consider this post more inspirational than informative, heh.