Dodge Dakota transmission, air, starting problems?

I've got a 2000 Dodge Dakota automatic, 3.9 liter, V6. First, when I drive, the tranny will shift into neutral on it's own, and has a hard time shifting, and when I get to where over drive would be it's running at around 4,000 rpm going 60mph. It rocks the whole truck when it's trying to shift to. Second, if the truck doesn't start for more than a few hours it won't start without a fight. I have to pump it really fast and while I'm pumping it will idle at 500 and when it gets up to 1000 if I hold it to the floor it'll rumble and then start, and if you let it set a while, it'll idle lower and rumble again and shut off. I've put a new distributor cap, the lead wire, the piece under the distributor cap(it's got a little metal clip on it), the crank shaft sensor, and it doesn't have a cam shaft sensor, so I called the Chrysler dealership and they said it's the computer and it'll cost $600 minimum. Is there any other thing it may be? Also(it's not to important), when I turn on the air instead of going to upper air and then the feet and then both, it just goes to defrost, on all of the switches. It did'nt use to, so I guess it just started. It does'nt have A/C. Thanks yall!