I was the evil mother who made their kid go on a ride even though she was scared. She did fine on all the other rides we went on. On Haunted Mansion, She did fine all the way through the line. When we were all herded into the room and they blacked out the lights, she kinda freaked out. I held her close, and told her to close her eyes. She stopped crying, and just closed her eyes during the ride so it wasn't scary. I won't make her ride it again if she's scared, but we do try to encourage her to try things even if she's nervous about them. I wouldn't take her on a thrill ride if she didn't want to though. I'm not usually a fan of thrill rides (I make a lot of exceptions at Disney) but I wouldn't force her to do something she was truly afraid of or I didn't think she could handle. She was a little nervous in the Pirates line too, but she loved the ride.
Beyond that, ice cream for dinner is fun. Too much junk in a short period on the same day without any nutrition causes meltdowns, and meltdowns cause yelling, which causes a distinct lack of fun. So while I may deny ice cream for lunch, it's probably because she had ice cream for breakfast, and I want to have fun the rest of the day.
Oh, and I really dislike that people assume that because you don't go back to the room for a nap that you're mistreating your child. We tried that, it didn't work for us. So we either sleep in and go late and spend the rest of the day, or get up early and leave the park early. We don't go early morning to late on the same day.
Disney World is a blast, but it's a family vacation. I will not let the entire trip revolve around my preschooler.