Cheers,
just found something more. It's not new, but dusturbing since ancient times in this game:
I just tried to sell some silk to smugglers at Antigua. I also had some medicaments in my cargo hold, just in case (I always have them, like food and rum). Unfortunately, the smugglers insisted on me selling the medicaments to them. There is no option between sell them - which I didn't want and fight the enraged smugglers after declining the offer.
I think it should be possible to sell and keep stuff. By the way, how the hell do they know what's in my cargo?
Need to look into this more, can't promise it will be added. As far as I remember the option is actually there but you need to be a damn good fighter for them to not get pissed at you and attack you.