A possible cause of your shifting problems may be the switch that is located on the top of the transmission. It goes by several names.... Neutral safety switch, Transmission Range Switch (TRS).
Costs less than $50 (US) at an auto parts store.
The shift linkage connects to it.....and it prevents the car from being started unless the transmission is in Park or Neutral. It also tells the transmission electronics what gear you have selected. It is quite common for this switch to fail.....but still perform the "neutral / park" safety function of letting you start the car.
Anyhow....this is a common failure...that is a LOT cheaper than a tranny repair / replacement.
I have a picture of the switch in my pictures at
http://community.webshots.com/album/201931518cScpNK
I have a '96, but the switch will be in the same place on your '95.... I would imagine....that you will have to remove a few things to get to the switch. I had to remove the air filter / MAF assembly and the flex hose to the throttle body. As the '95 has a different intake manifold.....that will be the only difference that I envision as far as getting to....and changing the switch.