@wickichick What - no answer! I'll take pity :D
If you disable the NPC voting, in Game Options>Eco-Living, before loading the save the first time (I think it can be done while creating the first sim in CAS/ or before loading an old save, right after choosing it in Main Menu - then you have control over which NAP's get enacted and get to stay clear of Sharing Is Caring, which is the one where all NPC will randomly take stuff from just about anywhere, including community lots, festivals etc. The items will go into the household inventory I think. Only your at anytime played/favourited households vote autonomously. Removing any households you don't want to vote from My Households tab in Manage Households will work too (unclick the heart).
The game has a bug where the visiting NPC in any area your active sim is present, gets all the NAP enacted anywhere in the game onto them, exhibiting all sorts of odd behaviour; so perhaps don't enact Sharing is Caring in any neighbourhood, in any world, is the best method until this is, hopefully, fixed.
The NAPs: Back To The Old Days, Promote Creative Arts, and Tech Support gives the NPC's an idle each, of reading books (only mysteries sad to say!), and playing with a clay blob and future cube. Those items are not cleaned up in unmodded game and end up in their personal inventory.
The CAS sim trait Recycle Disciple will require some managing: if the sim hasn't 'recycled' anything in a while they'll get a tense moodlet and start to 'swipe items', also from just about anywhere. This goes for any sim with that trait, your played ones and NPC's. The items are immidiately 'recycled', and do not stack in inventory.
Here are a couple of bug reports for the issues. Please click the button called Me Too, on the first post in each thread; so to make it clear how many players think this is an issue, for them to hopefully get fixed, and soon. Reading the bug forum is a good way of learning the ins and outs of the game:
NPC stealing from all lots:
https://answers.ea.com/t5/Bug-Reports/OPEN-ECO-Objects-disappear-from-lots-NPC-Stealing-with-and/td-p/9178299
NAP's from all neighbourhoods get applied to visiting NPC's:
https://answers.ea.com/t5/Bug-Reports/OPEN-ECO-NAPs-from-all-neighbourhoods-are-applied-to-visiting/td-p/9185155/highlight/true
Sims swipe items as a result of Recycle Disciple trait:
https://answers.ea.com/t5/Bug-Reports/OPEN-ECO-Sim-swiping-own-household-objects-Recycle-Trait/td-p/9175363
Future cubes and clay blobs in inventory:
https://answers.ea.com/t5/Bug-Reports/OPEN-ECO-Future-Cubes-Clay-Spawning-in-Inventories/td-p/9180759
And as a bonus you also get this, trash piles spawning in inventory, I've seen as many as 14 in one NPC's 'pockets':
https://answers.ea.com/t5/Bug-Reports/OPEN-ECO-Random-trash-piles-in-inventory/td-p/9191957