I'm don't really ave preferred seats on most rides. I just go with whatever I am assigned. It is good to be in the center of Soarin' but that depends too. If you are all the way at the edge of the center section, it is not that much different than being all the way to the inside of one of the outer rows. So really, it's not even a matter of getting B1, but getting B1 position 5 or 6. Honsetly, though I don't see a big difference until you get to the outside edges. The hight doesn't really matter that much, but it is more fun to be suspended higher in the air I think.
Quick tip for Star Tours - sometimes I notice I feel a little queasy after a ride on Star Tours. I realized it depends on my seating location. If you are in the front or back rows, or further our the the sides you will experience more movement than if you are in the center because that is where the axis of movement is. If you are in one of the extreme corners, the ride will have the most movement. Being in the center has less propensity to make me feel sick, though I have yet to make a seating request over it.