Park Avenue Problems

2003 Buick Park Avenue. 3.8 V6 engine.
Question: The heater doesn't always put out heat.. I replaced the Thermostat. The old one appeared o.k. , but I replaced it anyway...Example Backed out of garage to go to a class luncheon, drove 2 miles to pick up my lady.. I let the car run ,went in & got her ,came out & drove to the luncheon approx 1 mile...

1995 Buick Park Avenue base.
Engine Size : 3.8 v6.
Speedometer has stopped working and car will not shift out of 1st gear. i replaced the vss and that did the trick for about 3 months and it is at it again. this always happens when it is damp outside. i have checked and cleaned the connections. all i can figure is a short somewhere or a bad module. any ideas? is this a common problem with the 4t60? thanks!

2003 Buick Park Avenue.
Question Here: The Transmission is shifting goofy.. At times it will shift real smooth & then it will shift real hard.. What could cause that?? I had the dealer do a fluid flush.. I wanted a fluid & Filter change , BUT They said no You want a Flush.. Did I do wrong in doing that too ???

1995 Buick Park Avenue. 3.8 V6.
2 problems. Driving a car home left to me in a will. The car just quits. Let it sit for a while and it will run again for a while. It seems when it warms up it just dies and won't restart until it sits for a while. (crank sensor?).....MAIN PROBLEM >.....The horn honks and the lights flash and the car won't start.(delco-loc / theftloc?)..Is there a way to wire around or to completely disable this option? I'm going to give this car to my wife. She goes to work at 5am and drives 7 miles to work.