Which set of scripts are you using for your shard, ie. POL Distro, World of Dreams, Zulu etc.? There should be a spawn system in there. As for the loot on monsters, well, that again depends on the script set you are using. There should also be a loot generation system already in the scripts as well.
InGame building with POL is usually done by using the .createitem command and making buildings and structures that way. You might have some commands for changing the X,Y and Z of the item once it is created and there are no doubt commands for doing lockdowns of items either one by one or en masse. Again I'd need to know what main set of scripts you are using for your shard in order to advise you further.
There really are no integrated world builder tools like you might find with some other emulators. Map or terrain building on an existing map is usually done using WorldForge or some other utility. I have used WorldForge along with World Builder by Punt. World Builder is not in development any longer but it is pretty good. As for creating new maps from scratch, there's Dragon and Genesis mentioned
here.