I have found a way to fix at least the problems with the un-textured weapons.
Step 1: download morghs editor (a warband modding tool)
Step 2: use the item-editor and look for the weapons (zb. broad arows are Nr. 175)
step 3 add a new weapon based on a funktional one (i used the bodkins as an exampel)
Step 3:go into the mod itself (Program Files x86/Steam/steamapps/workshop/content/48700/1896043652) and open item_kinds1.
Step 4: your new iten should be now on the bottom of the data. cut it out and replace the arrows with it (if you just delete the arrows or an other item then the IDs of all the items will change and it would be a big chaos in the game.).
and Step 5: if you have done it right go back to item editor and you should see a message that on entety or item is missing (because we have replaced one)
and now just make an random new item as a placeholder and it should be done.
And since that it havent crashed anymore.
There are surly some more bugs but i am not good enough in modding tho fix them. (all above are youtube- tutorials and trying)
I hope this will help at least a little bit and if someone here is better in modding then it would be nice to help fixing this nice mod.
If the Creator dont fix this mod then we just do it by ourself.
(and sorry my english gramar. i hope its understandeble what i say ^^)