Hi and welcome to CL
All the problems are fairly common and also easy to sort,easier if you can solder.
HVAC LCD is out (go figure)
Look on ebay for the LCD screen,replace it yourself for around $60.00,there is a tutorial on fitting.
or even $44.00!
- A few cluster bulbs are out (parking brake warning lamp and CEL)
Push fit bulbs readily available.
- Error code 4 on Pioneer CD changer
Have you put the CDs in the cartridge with the playing side not the label side facing up,the CD mechs do have problems and after market is probably the way to go either with a single or double DIN set up.
- Remote door locks dont work properly (press the button and they just keep trying to cycle)
The door lock motors fail ,sit in the car and activate the locks by the keyfob,see which one doesn't lock and go from there.I have more infomation on replacing the motor with pictures if you need it.
- Half dim speedo needle.
The coating on the needles fractures causing poor illumination,I think Jim Walker is Southern Cal still repairs them.