2006 Chevy Trailblazer won't start, locks go crazy

Hi. I have a 2006 Chevy Trailblazer LT.
Recently the truck won't start and
displays the lock symbol on the
dashboard. The power locks go crazy
and I hear them clicking on and off. After
trying to start the truck with the key in
the ignition about 7-8 times or about 10
minutes from key in to start I can get the
truck started. But then the driver's side
door panel won't roll any windows down
or lock/unlock any doors but the other 3
windows and door lock buttons work
fine on their own doors. All the lights on
the dashboard stay light and the truck
will drive ok but if I drive for 30 minutes
or more and come to a complete stop it
has died and I had to wait 10-20 minutes
before I could get it started again. Not
really sure what's going on. It does has
an aftermarket remote starter but I
believe because of the issue it's not
working. The battery is 2 months old as I
thought it was that, and the starter was
replaced also along with the serpentine
belt because I was told it had cracks in
it. Local mechanic I took it to said he ran
codes and couldn't find anything and
replaced the obvious like battery, starter
and etc which probably didn't need
replacing. I have noticed that sometimes
if I stick the key in driver's side door in
the unlocked position for 30 plus
seconds I can hear the locks clicking
on/off and when they stop I can usually
start the truck but the same problems
stated above still occur. Sorry for the
long post and read just trying to see
what it might be before I try to take it to
another shop and get the run-around.
Thanks in advance for any help.