So I copied the latest DF version (34.05) over my old Dig Deeper folder (taboo, I know), and then added a rapier weapon to my dwarves, elves, and humans.
As a note, I let the pasted in files overwrite EVERY file there, so much/most of the DD information was removed, and the raws for basic creatures and entity_default were the standard.
...and genned a world.
I decided to test whether it had that annoying crash I sometimes got in adventure mode when talking to people, so I started playing it in adventure mode.
I could play as a goblin, kobold, elf, or human outsider.
"DAMN!", thought I "All of the dwarves and humans must have died...." but then I thought "Wait... goblins and kobolds? I can adventure as those without lots of raw editing?"
I decided to play as an elf. I started off outside a mundane house, and thought "Huh. I wonder who built the houses if there are no humans?"
So I went inside. It was filled entirely with goblins. I approached a goblin miner and talked to him. The discussion was quite normal. He told me about his capital, where a gremlin lived, and to kill a gremlin master in some camp north of here.
Going to the fast travel screen, I found that I was in a town entirely populated by goblins, and that there were many other towns populated by goblins nearby.
Then, confused, I walked off to a nearby castle, which was entirely filled with goblin soldiers, and some goblin peasants were in the lords room. Then I retired, and decided to embark.
Then it got even stranger.
I embarked with seven elves, which had no access to dogs, so I only brought cats. Then I ordered my elves to mine out the side of a nearby mountain, build a mechanic's workshop, and make mechanisms, which they did.
Is this possible with entity_default being the default entity_default? The only thing I changed after pasting over DD was that I gave humans, elves, and goblins access to a new weapon, the rapier.