To get dwarves and goblins to build towns and hamlets, you need to modifiy /raw/objects/entity_default.txt and change [DEFAULT_SITE_TYPE] to [DEFAULT_SITE_TYPE:CITY] under [ENTITY:MOUNTAIN] (dwarves) and [ENTITY:EVIL] (goblins). Note - this will just make dwarves and goblins build human type cities, and SELL ONLY HUMAN SIZED ARMOR AND EQUIPMENT (in the rare cases that shops sell anything at all). If you want a source of dwarf/goblin equipment, then you can look in the keeps at the center of towns/cities, or in fortresses. To get Dwarves/goblins to build above-ground fortresses, you need to add [BUILDS_OUTDOOR_FORTIFICATIONS] to [ENTITY:MOUNTAIN] and [ENTITY:EVIL]. You might also want to add [BUILDS_OUTDOOR_TOMBS] if you'd like to have dwarven/goblin tombs to explore. Unfortunately, for anything resembling proper dwarven/goblin settlements you will need to wait until the next release. You will need to generate a new world for any of this to take effect.
As for the bogeymen, you can get rid of all the bogeyman by making the "Number of Bogeyman Types" zero in advanced world generation. I don't think there is any way to reduce the number of bogeymen per ambush. However, if you can kill one bogeyman, and you are faster than them, you can probably almost as easily kill a large number with a little strategy. What you will need to do is run away from them, and then wait (".") until one is next to you. Then attack this one bogeyman until other bogeymen also move next to you. Then run away again, and repeat. In this way you can only fight one enemy at a time. Just make sure that you don't run away too far, as if a bogeyman gets too far away from you it will disappear and respawn in front of you fully healed.
Also, since the title of this thread includes "good adv mods" you might want to check the mod in my signature which allows armor to provide some protection from bolts/arrows.