jcsfearless, first thing, make sure the drivetrain is spinning completely free. Take the pinion off, pop the rear camber links off and spin the spur, the trans should be smooth. Each rear axle should spin smooth as well and check again after you tighten the wheels down. They could cause binding. Same up front. I run JC B5 wheels on the front and if you don't grind them out at the hex, they bind.
This past weekend I ran 17.5 geared at 69/31 with 50deg timing on a D4, never reached over 100. Make sure the motor is timed correctly also, not sure on the Speed Passions.
For the rear shocks, my RB5 used to do that, I just lived with it. But the setup you're running looks like the rear sits low and rolls. Just to try, I'd stand the rear shock up on the tower two holes and go to the medium rear shock bottom. See if that helps. You may have to run a slightly stiffer spring standing them up.I'm not sure what the AE springs are, but I usually run Orange or Yellow Kyosho on carpet and turf.
Hope this helps, but the big thing is make sure the car spins free.