OK, shifting issue solved. I was taking a typical palm-facing-left, thumb-on-top grip on the shifter and probably applying a bit too much sideways force on the 2-3 shift. A friend of mine told me to to take a palm-down grip with my forearm parallel to the floor. As soon as the shifter pops out of 2nd and into neutral, it will be in the 3-4 shift track, so just push it straight forward. I tried that advice and it worked like a charm, even shifting near the redline. I burned half a tank of gas just ripping around a deserted country road. Every shift felt like butter. Fun!!

Glad it worked out and I saw on a tv show years ago that when not shifting gears it's best to keep your hand off the stick

Yep, leaving your hand on the shifter tends to bend the splines on the shift fork. Most drivers don't think about that much, but it's just as bad as riding the clutch with your foot. Different method of damage, but still screws up your transmission either way.