The cruise ships don't weigh luggage, but the airlines do. The ships have skates guests can use, but note the ice rinks on Royal Caribbean ships are only open a few times on a cruise, and it is a very small rink.
Now, about the reviews you read here....I personally approve all reviews and do not base the approval on whether the person liked their cruise or if they only had a lot of bad things to say. People seem more likely to submit a review if they have an ax to grind than if they loved their cruise. Human nature, to be negative. It is often in reality one or two little nits that happened and the reviewer feels the need to make it into a big deal. Read the reviews with a little bit of jaundiced eye.
Specific complaints we often see about any cruise ship sailing from San Juan...."there were too many Puerto Ricans onboard", "too many people speaking Spanish", "all the passengers stayed up late partying and kept me awake". Each of those is a 'duh' comment, usually made by people who think the whole world needs to do things 'the American way'.
Don't bring water from home on the airplane. If you insist on bottled water (and I agree with susanmaz on the quality of the ship's water), just buy it on the way to the ship. And by the way, when cruising from a port you have to fly to it is always wise to get there a day early and spend the night in a hotel, then board the ship the next day.
Bottled water needs to be carried aboard in your carry-on luggage, and the cruise lines do have general rules as to the amount they allow. Generally this is a pack of 12 or so bottles per guest.