We've never had a problem bring a single case of water or soda on any cruise, but on several of the cruise lines we had to carry them on (we usually catch a shuttle to
Walmart on one of the first places we stop, and get our soda then, since it's not always feasible to carry it on). Irons aren't allowed and if they find them your luggage goes to the 'naughty' room and you get to watch take them and as you said, they are held until the night before the cruise ends. But steamers are usually allowed

. Booze depends on which cruiseline and if you are willing to pay the fee to have it marked as yours. Our friends paid the extra, because they wanted their own wine at diner. There really wouldn't be anything that I would have hand carried to Haiti, although several ships took money for donations.