Thanks man. i actually figured it all out now. I will share some of my findings here so it maybe helps you make a video for others.
For things like Electronics, Sparkpowder, etc. You need to also change the engram to point to your new resource and remap it in “Remap Engrams” in the PrimalGameData.
The Slingshot is a little different. For the Slingshot you have to change the Primalitemweapon, the WeapSlingshot and the Engram Entry, otherwise if you change stone it will not be able to use it.
I still gotta check the jerky but cooking meat works.