May I ask what is your scope? I mean how would you expect for that "start from nothing fort" to interact with the other civs? Would it be completely isolated? Would they trade/fight with others? i think the answer to these questions is rather important because both trade and war provide the player with some access to tools and equipment.
Fighting and trading are both certainly within the scope, though the latter is obviously locked behind getting access to some form of building material to make a trade depot, and the former a matter of
surviving defeating a gobbo attack or something with sub-metal gear. And neither is going to give the player anything immediately useful, as the race is physically too small(but not as small as kobolds) to equip goblin/dwarf gear directly, and do not have access to metal forges to melt stuff down. And as you did mention Kobold Kamp, i do have it in my references folder for this mod, as i intend to do something similar to it's scrapping/salvage mechanic, to allow my race access to some metal equipment.
The biggest issue with starting without tools is that the player can't dig or cut trees and thus they can't create dwellings and fortifications. This would make the town extremely vulnerable to tantrums, dangerous animals, werebeasts, (semi)megabeasts and necromancers any of which can end the fort early on. My experience with such forts is that evil biomes are instant fail and savage ones are a gamble.
Well, my ideal plan has the player able to build a proper (tree-)fort before ever chopping down a tree or mining a piece of stone. Though, that is the super ideal scenario.
I can't remember the mod (Orc fortress perhaps?) but I remember reading about one where they used custom reactions to simulate praying to the gods and had a chance to give some item in return. Writing all these might become a chore, but you should be able to give a civ access to anything they need through those.
That's really the only thing i don't want to do; to produce stuff out of thin air. I might dip into magical reactions later in the tech tree, but it'll be after the hurdles of the early game, which i (ideally) wanna focus squarely on foraging and survival.
I won't be any help with the modded side, but to expand on the information from vanilla - embarking with nothing still gives you a wagon (I don't recall if these can be modded out, or if you'll just have to make them immediately boil or something). The wagon's 3 logs can be used to make all sorts of workshops, which gives the player access to meat, leather, and bones as well as whatever they can fish up. They can cook and even create bags. Plenty of crafts can be made from bone and shell. I've embarked with nothing and by the time autumn arrived, had a squad of shell-armored crossbow dwarves.
Hehe, i did think of this problem myself. So far, my plan to deal with that is to change the material of the wagon "creature", so that it is not usable for making stuff out of
.
I have actually put some further thought into this problem myself, and i've come up with some potential avenues for giving the player materials to use:
Trees at times drop leaves and fruit in vanilla DF. I'm fairly sure the same system could be used to make them drop something like twigs or branches, which could, with a little imagination, be combined together to form a basic, wooden building material. The problem: it would likely limit the starting embarks to places with trees, which most embarks have, but excludes some of the more extreme embarks.
A fake rock "fish" could be created, which could be fished up, and then crafted into more useful things. Problem: this will limit embarks to ones with a body of water. Also, i'm not sure if making this "fish" ubiquitous might displace actual fish. Also, dwarven embarks will also then fish up random, utterly useless rocks.
Same as with the trees, plant gathering could be modified to also produce plant stems or something, potentially useful for crafting.