I would not start with tot, personally. I'm fairly wimpy...used to go to
disneyland a lot when I was a kid living in california, but it took me a long time, until college, till I would try space mountain (this was before splash). I did splash mountain and big thunder for the first time when I was in my mid-late 20s at wdw, and I also did TOT (haven't been since RnR came along).
Splash is my favorite ride but I'll be honest and say that I ride it in spite of the drop, not because of it. Its just a wonderful ride. The first time thru I was terrified because I didn't know what to expect and kept expecting the drop any minute. After the first time thru, and I realized the drop was really obvious and not a suprise, I had a much better experience. But every picture since still has me with my face buried in my husband's shoulder. lol.
BTMR is awesome...to me, its the perfect roller coaster. I know most people think its tame, but I just think its fun. I am amazed at how many years I missed this because I was too scared to try it. And every time I've ridden it since I finally went on the first time, I still get a wee twinge of fear, but then it goes away as soon as the ride starts. There are no big drops, just lots of curves and lots of fun. I think what helps me with roller coasters, even tame ones, is to remember to relax...I used to tense up and get rigid, which makes the experience not fun...it gets jarring. But if I remember to relax and breathe (breathing is important, lol), I love it.
TOT was a unique experience for me. I was excited to go on it, thinking one drop wouldn't be too bad, and since I love twilight zone it would be fun. The guidebook had said one drop, the problem was we went on the trip I rode it the year they changed things...added multiple drops. I thought something was wrong with the ride and it would never end. It was awful. Had I known ahead of time that it was now multiple drops, I think it would have been okay, still scary, but okay, but because I was thrown off it was a very hard experience. Didn't help that I forgot to remind myself to breathe thru it...I held my breath thru most of it. I have yet to get back on it, although I promise I will again someday.
Good luck to you!!!! I would seriously start on something tamer like splash or btmr, and work your way up to tot.
The theming is very good, I will say.
Will I ever learn to keep my mouth shut? 
It was you that I'd asked to get the tag!!! 
Plus you get to see all of the cool stuff in the lines! 
