OP, don't let all the squabbling of other posters get to you or make you feel bad that your child has tantrums. I believe that the parents of those kids who have "never" had a tantrum, or whose tantrums have been nipped in the bud from birth, are just lucky enough to not have had a truly strong willed "spirited" child. Kids, like adults, have different personalities. One of my best friends is a grade school principal and before that was a counselor, and before that a teacher. She is probably the best Mom I've ever seen. She has one perfect angel child and one totally spirited makes her want to pull her hair out child who threw tantrums like you would not believe when he was young. She knew all the tricks and methods, he was just a totally strong-willed child (look up gifted overexcitability on the internet). It was inherent in his personality- it had absolutely nothing to do with her parenting skills.
My BIL's child is an extremely docile quiet child. She is a follower type. As a result, he has no comprehension of my crazy child. It is inherent in DD's personality (again "gifted overexcitability"--it is intrinsic and something that you have to learn what works to calm them and stop tantrums with trial and error). Mine tends to be a leader, not a follower. At age 3, her pre-school teacher told us she predicted she would either be a CEO or a star when she grew up. BIL thought that he could do a better job of "disciplining" her and controlling her behavior than us. We sat back and watched. Can you guess who won? I will give you a clue-it wasn't BIL.
(She totally outsmarted him, chewed him up, and spit him out.) The same methods will not work on all children- because all children are not the same.
For DD, an authoritative style like some have promoted was absolutely the worst method for her. A kid with her issue acts out a lot when very young because of frustration due to a lack of control over things- the authoritative style only escalates tantrums and makes them more frequent and worse. We tried it and it was a disaster. A kid like that needs to know they are being heard and understand the "no"- you have to explain the WHY of everything. I understand you want that, but You can't have that BECAUSE.... I understand you are angry that we are not letting you do that, but you can't do what you want because.... There are also little tricks you learn to deal with that type of personality. For example, even at age 2, if I picked an outfit out of the closet and said "you are wearing this today", I might frequently get met with huge resistance. I learned that if I brought 3 outfits out and said pick one every day- no issues. She felt like she had some control. You just have to figure out what methods work for your child. Kids are different. Some are tantrum throwers, some are not. Some the "authoritative method" might work, others it absolutely won't and can make things worse. Some taking things away works (ours it didn't because she would just sit there and create her own imaginary play if we took toys away). Some ignoring works. Some using explanations work. Some just holding them until they stop works. Some seating them in a quiet area, sitting with them and telling them nobody is moving until they stop works. With some, different methods are best on different days depending on their moods. What worked terrific yesterday, may not work at all tomorrow- so you have to try something else.
And again, don't worry about WDW. We just got back and we saw and heard lots of fits from littles. No one even blinked an eye around them. I would say the vast majority of the people around you at WDW will understand and will not be judging you. It is a common WDW occurrence.
For the previous poster that talked about the horrors of picking the pink instead of the blue- that had me laughing out loud. I can totally relate. DD is 8 now, and to this day- if blue is a choice that is the one I'm going to pick. I'm pretty sure she is old enough now that it wouldn't be an issue- but I'm not taking chances!!!
Oh and FYI- at our house, I'm considered the stricter one. DD is far more scared of me than she is of DH!