89 Sable Multiple Problems - Need Help

I have an 89 Sable with only 103000 miles on it. It sat for about 5 years without being driven before I got it. I have replaced the gas tank and fuel pump with one from a 91 Taurus I have. I made several electrical corrections (missing grounds, replaced the alternator (was bad) and voltage regulator, etc), and it was running and driving fine. The only issue it had was that the radio will not turn off. Then....out of the blue (all at the same time) it leaked a puddle of transmission fluid, it started having a bad miss, and the brakes went out (as if no vacuum on the booster). I found that when I replaced the vacuum hose to the fuel rail regulator it seemed to run fine again, with only a slight miss. I also checked the plugs and they are fine. I bled the master cylinder and brakes and it seemed to hold fine for about a day. Then the following happened:

It now has the following issues (all at the same time):
1. Intermittent the turn signals, rear defrost button, dash turn signal lights, will not work.
2. Intermittent the heater blower motor will not work.
3. Engine seems to have a miss.
4. Brakes do not hold like they should; seems as if there were a vacuum issue.
5. Transmission shutter in overdrive.
6. Rear speakers don't work, but have static and popping if you hit a bump.
7. Radio will not turn off.

I have thought about changing out the speed sensor, MAF sensor, fuel regulator, AIC module to see what affect they may have. Could also pull the ecu from the 91 and possibly the other computer above the radiator if necessary.

Any help will be appreciated.