Dead instrument panel, ignition key stuck.

I have a 5 door '99 Blazer with 4,3L V6 engine. For the past 6 months I've had a problem with my instrument panel and ignition. It all started with the engine malfunction symbol showing in the instrument panel, and everything else being normal. I called my local Chevy garage, and they said it probably was the EGR valve and advised me to use high-octane fuel every now and then. This didn't help and the problem evolved. Now the instrument panel dies (only showing oil pressure and battery) and I can't get the ignition key out. In addition, the engine seems "weak" and I have to use a lot more power just to get it rolling. This is not constant, every now and then the instruments wake up after a mile or so, and the engine starts working normally. However, almost every time when I stop the car and shift to park, the instruments die again and I cannot get my key out. I manage to turn the engine off but I can't turn the key the last bit and take it out. If I leave the key in and wait an hour or so with the car stopped I usually get the key out. While the key is in and the engine is off there is almost constantly sounds of some electric motors underneath the car.
The funny thing is that if I press the Trip Counter button on the instrument panel, the whole thing wakes up and works normally, and everything disappears again when I release the button.
I've been to the Chevy garage with the car having it error searched and costing me a LOT of money. They concluded that the transmission position switch was burnt and had to be changed, and they did. When they did, the computer reported two errors in the VCM (control unit for the engine). Thus, we tried changing the VCM but when we did, it reported the exact same errors.
This thread got very long, and I apologize for that, but the Blazer is a very expensive car in Norway and I just cannot accept that they can't work it out. So my question is : Have any of you experienced anything similar or do you have any ideas of what I/the garage can do?

Sounds like you have a faulty ignition switch. When your unable to take your keys out the next time. Try moving your gear shift around from park to drive a few times. This will cause a vibration on the ignition switch, and possibly let you remove your key. Thats one way in finding out if your switch is bad.

When was the last time you cleaned your Battery Connections? Also, How old is your Battery? If your Blazer does not recive a steady diet of 12 volts, some strange shit starts to happen to it, Like, Instrument lights not working correctly, and Codes being sent to the car's computer as well.