and if it is resources and he spent them? should he kick him for thief?
There is no thievery in the Guild's stash.
However it is assumed that if you don't need a specific item or want to share it with others, then you put it in the Guild's Stash : that's how you could find some lvl 8 weapons and armors earlier today
About your coal, I'll have a look at the guild's logs when I've finished my resting time
Additionally, not having a mass message feature for Guild's Members is terribly handicapping for communications : the in-game Forum is not very user-friendly (lack of clarity in new messages)
Have fun,