Then we took her to Finding Dory last week and she buried her head in my shoulder the whole time and kept begging to leave! I'm hoping the whole "will she find her parents" plot was the reason and doesn't mean she'll be scared of more concrete experiences/rides.
When I was 4 they re-released Cinderella in the theaters and I begged to see it. The moment the stepsisters showed up I was DONE. I couldn't handle it. My mom, thank goodness, left with me. And that was in the days before theaters were kind and would give you your money back! It's not like now.
The *emotional* impact of a movie or a ride CAN effect a child more than other things. My son is gotten to, emotionally, by background music to a point where I really thought he was going to be a musician. (instead, he's a dancer! so it's all about reacting and responding to music emotionally with his body) The physicality of a ride rarely scares him, but the storyline really really can.
I will say the main thing with ToT isn't the haunted house element but the drop.
Not for all kids! DS was 4 when he hit TOT out at DCA the first time, and I can't remember if it's the same at DHS but at DCA you are looking at the mirror and you're hit by lightning, turn blue, and turn into a skeleton. My son HATED that. He absolutely loved the up and down of the ride, that was superfun to him. But I believe he was NINE when he finally stopped talking about how he hates that we died on the ride. "Uh, kid, we didn't die, we're right here"... Had no impact on him, that we didn't die. The emotions of it overrode being rational, and he just wouldn't deal with the ride for years.
There's NO way I'd take a 4 year old on Dino. It *might* work out just fine. Seems that there's a much higher chance of it NOT working out. I am not willing to take that risk with my trip. Oh, and my child's psyche, of course.

On our first WDW trip DS was 6.5 and said he would go on it, then in line changed his mind. I went over a very irritated DH's wishes and took DS out of line. Ooh DH was annoyed with me. DS and I waited in the giftshop and saw kid after kid after kid come out, shaking and in tears. (and many perfectly happy kids, of course) DH came out and thanked me for being the cooler head, because he could tell that DS absolutely couldn't have handled it.