Dropping items is completely voluntary. You take the risk when dropping items. So if you lose them in this manner, it is your fault. If you want transactions to be more secure, just create a locked chest and add anyone to it that you want to do the transaction with.
If this is possible, this is a very elegant solution. Limits the intereference with new users and focuses in on the main problem (lost star tools).
Also, It will prevent the "Oh no your melon sword disappeared and i just happen to log off the second i was giving you a repair" scams
I do not agree with this. It seems very silly and impractical, as well as frustrating. Sure, i simple command like /drop or /throw (whatever you wanna call it) would be okay, but it wouldnt really be worth anything to the users. -1 for me, i don't really see this happening.
The only reason why star items are stolen during the trade between money for the sword is laziness. People will go to spawn and do the transaction with a simple drop. Sadly, sometimes, the reciever "doesn't pick it up," but actually just steals it. Then, you're scammed, because there is no way to see if he got it or not. Or someone may just put a chest down without any locks and an investigator with /v on may wander by and see that chest, open it, and take the sword. Basically, to sum it up, when trading valuable items make sure to use a chest that is locked in some way so both members can access it. I really don't think this suggestion is necissary because it can be solved with just a bit more effort put into trading something.