I'll give these a shot:
-I think buckets pails and shovels are available for purchase, probably on
Castaway Cay. It is probably much cheaper to bring your own. I don't know that they have any to lend. But, I've never cruised with kids, so I'm probably not the best one to answer this question.
-I've had the same problem with waitlisting. The method I've had success with is to call every few days and check to see if there have been any openings (or have your TA do it, if you've booked through one). While people do get changes from the wait list, I am told by
DCL reservations staff that the wait list is only checked once a day. So, if there is a cancellation, the opening exists on the system until the next time the list is checked. If someone calls and there is an opening, they'll get it. Your best chance is during the week just prior to the 60-day period. Most cancellations happen during this week, as it is the last chance for people to cancel without having to pay a penalty. I've used this method to get what I wanted from the wait list. It only takes a few minutes if you have your reservation # handy.
-A category guarantee means that you are guaranteed to have at least that category. This usually happens when they fill the bookings for a certain cabin category. They book a few more than capacity to allow for cancellations. They will assign you a cabin # closer to your sail date. You may even get an upgrade, but don't count on it. You won't do worse than a category 6, though.
-Again, never sailed with kids, but I believe you register for the kids clubs on the first day, and then they kids can go to as many or as few events as they like.