What can cause my (OD off) light on the dash to flash on & off on a 2001 ford winstar?

I took it to a mechanic shop to have transmission scanned. I forgot the code it showed but they said it was pointing to speed sensors. But the other guy at the shop drove it down the road and the scanner that was still hooked up shows the correct speed so that means that speed sensors r good he says, so they want me to leave one day and they will look for broke or loose wire. But I know that's going to cost way to much $ so if anyone has a solution please share?
BTW: the speed ohmedar sometimes only goes up to 20-25 mph. When I'm really 50-60mph. Until the OD light started flashing now it stays on 0mph. And sometimes it starts working correctly. The dealership replaced the whole speed ohmedar unit on the dash awhile back trying to fix speed ohmedar but that didn't fix it. And the cruise control stopped working also

Can a car run without a power steering pump?

I'm looking at buying a cheap car i desperately need but he says the old power steering pump was taken completely off The car, it's a 91 ford probe and I know it can drive without power steering but will having the old one completely disconnected stop the car from running and driving?

Is it legal for me to taxi some highschool kids?

Okay, so i got my car and license Really early, due to my birthday. I didn't get anything too attractive, but i just got a simple Ford truck, enough to fit 5 people (including driver and middle seat in the back.) Now, some kids HATE the bus, so they ask me to dive them home. I've noticed how they live pretty far, therefore making me lose some gas. Now, I'm charging them $4 for every stop light we encounter, so i can pay for fuel. Now, I'm not starting a whole taxi service or anything, i just want to pay my fuel and go home. Is this legal? I'm not looking forward to taxing people around in my sophomore year…

What would be the best year of car to buy for a new driver?

I'm wanting a truck but I'm having an issue determining what year I want.

I'm not ever going to go into debt for a car.

I was thinking a 70's or early 80's Ford due to fact that the interior is mostly steel instead of cheap (cracking) plastic, and I can easily work on it and fix it (Thus it will last me pretty much forever) and those trucks are the year I was raised around and have the feel for most.

That's my 2 cents, what do you guys recommend?

P.S. I was raised with the safest driver around. And I take my driving more seriously than anything else. I'm not a distracted bad driver. (Although I'm slow). I also do not drive on the interstate unless absolutely warranted.