Propably not ****; but the most critcal point i see in your description is:
to a dummy troop's slots - or something else that stays between scene changes
Your proposals about the get_item_slot jazz i found in header operations but how can i save /load any stuff that lasts over a player rejoin server?
This is possible I know "Crpg" deos it but i fear other programms then module system are in use here.