I thought you could give it for free. I know I have as a noble, to commoners and other nobles alike.
I can't imagine this was ever intended, but realistically, you wouldn't be able to keep it up unless you have a lot of items and/or dedicated adventurers. In the cases you mentioned, those shouldn't be problems.
The only unique item "exploit" I know of that is not allowed is attempting to circumvent the mechanic that disallows trading among your own characters. Otherwise, even though it is potentially exploitable (a lot of stuff is, actually. It depends on the player whether to follow through.) it does make some sense, as in collateral and payment. But, again...most likely an unintended way to send gold directly to someone.
