1) I did some research on this a few years ago. The parts store was sort of right about the fluid, but not entirely. The manual says to use 10w30 SF/SG grade oil which was common at the time our cars were made. Now the most common grade is SJ, which is actually a little too slippery for our transmissions. Synthetics are usually even worse for them. Scynros take a certain amount of friction to work or you'll grind gears. So take that jug back and look at the back of the bottles for an SF or SG. They usually say they are for older vehicles or even motorcycles. I found some at wally world but most stores will carry at least one brand. Some people (myself included) use penzoil syncromesh which can be found at autozone. It does smooth out shifting but I have no idea what it does for long term bearing life. BTW you only need 3 quarts of fluid.

2) You might be able to change them while still on the car, I've never tried. When you go to pick up the new ball joints ask to borrow the ball joint press. Most places have a lone a tool program. It will look like this http://www.harborfreight.com/cpi/cta...temnumber=4065