Hi Eric,
For the first problem you should make sure the throttle plate is properly adjusted. Then I would check the adjustment of the throttle switch. With the
engine off and when you open the throttle linkage you should hear a click of
the idle switch. You should hear this everytime consistently as you open the
throttle from closed.

It's unlikely to me that you have a bad thermostat if it's new. I would blame the temp compensator board. If you have some soldering skill you can remove the board
and replace the IC, 1 transistor, and there is an electrolytic cap on there.
This is usually the parts that go wrong on the board and individually they
don't add up to $10. Much better than a $50 board.
Dave 82 242ti