Beginning Driving/ Ana Problems

Is it just these horses or do most horses learn quickly?
I caught Toffy and attatched two long lead lines to the side of her halter. It's been wet, windy, and cold, so I chased the other three fillies out of their little section of the barn and commensed to teach Toffy how to ground drive.
We took twine string and attatched it to one rope, then the other so that the twine rested around her back and kept the ropes up.
I tried getting Toffy to go, but it wasn't working. She kept turning to look at me. So, to give Toffy an idea of what she was supposed to be doing Terry took over the ropes and I walked in front of Toffy. This definetly helped. She followed me and didn't get too worried about the person behind her. The trick was when she did try to turn and look at the driver was to pull her over to stop her from doing that. But once you pulled her over she just turned the other way, so you had to counter that too.
After a little while of this she was able to do it on her own. Initially she tried to turn and look at the driver, but she got it.
The hardest thing to do is keep her straight. When we put the carriage on her, she won't be able to turn really sharp. She'll have to learn to do a little bit of a side pass to turn. Terry said that he never taught them how to sidepass in the carriage. It's just something they pick up on.
I was going to use the bit right away, but Terry said that if they went to fight you, that would be hard on their mouths. And with all the turning and figuring it out  that they did that would have been very hard on their mouths. The bit will wait until they can ground drive pretty well.
We did this with all of them except Coffie. Aleythia picked up Coffie's feet instead. But it probably took us a half hour with Toffy, and the other two probably took 15 minutes.
They can walk, speed up the walk, turn minutely well, stop, and back up. But the only horse we did it without a leader was Toffy.

Before we ground drove Toffy Aleythia got on Ana bareback. She did a little bit of ground work, because Ana was moving around allot while being tied. With the ground work she calmed down.
She got on and Ana was hyper. We had told HM that Ana was more calm with as little tack as possible than with it. She suggested that it could be that the saddle doesn't fit her right. But after today we don't think that's really the problem. We will try and make the saddle fit her more correctly though. Parelli has pads that he puts underneath the saddle, but Aleythia thinks that a towel could work too. The only other tack she had on was a bridle, and I suppose that could make her anxious, but I just don't know.
Aleythia wants to ride Ana bareback for the rest of the winter and see if that has any effect on how calm Ana gets.

And one other thing...
Do you ever get the feeling that if your horse spooked you wouldn't be able to stay on? It's not a feeling you always have, just something that shows up once in a while.
Your horse may be calm or at least seem calm, and you may look like you have a solid, easy seat, but you really don't feel like you do. I have this experience most often when I am on the trail riding Misstack. I think the most times it happens when she picks up a more, not necessarily bouncy walk, but it pushes you up further. I think she is probably doing an extended walk.
My most recent experience with that feeling is when I was riding one of HM's horses, Buddy.
We went out on a trail ride and he also had the extended walk thingy going and I just didn't feel secure. I was fine inside the arena. HM asked me how Buddy felt, and I said that he felt fine it was me who didn't feel fine. She said I didn't look like I was insecure. After a little while it went away.
It could be that I am not riding it right or that I am slightly tense. Or maybe I'm too loose. If I ever get that feeling again, I will have to experiment with how I ride it.